diff --git a/.gitignore b/.gitignore
index cb0f8ab..865e848 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,3 +42,7 @@ compiled/
 /app/Config/database.php
 /vendors/*
 
+
+.rktsndbx-cache
+data
+pkg-cache
diff --git a/.htaccess b/.htaccess
new file mode 100644
index 0000000..6cd1e2d
--- /dev/null
+++ b/.htaccess
@@ -0,0 +1,17 @@
+FallbackResource /index.php
+
+DirectoryIndex index.php
+
+Options -MultiViews -Indexes
+RewriteEngine On
+
+RewriteRule ^bootstrap-racket$ rkt.php [L,QSA]
+RewriteRule ^bootstrap-racket-part$ rkt.php [L,QSA]
+RewriteRule ^racket-pkg-index$ rktpkgs.php [L,QSA]
+RewriteRule ^package$ package.php [L,QSA]
+RewriteRule ^package-part$ package.php [L,QSA]
+RewriteRule ^login$ login.php [L,QSA]
+RewriteRule ^bootstrap-admin$ bootstrap-admin.php [L,QSA]
+RewriteRule ^prompts$ prompts.php [L,QSA]
+RewriteRule ^users$ users.php [L,QSA]
+RewriteRule ^admin-config$ config.php [L,QSA]
diff --git a/auth.php b/auth.php
new file mode 100644
index 0000000..17ce216
--- /dev/null
+++ b/auth.php
@@ -0,0 +1,722 @@
+<?php
+/*
+ * auth.php
+ *
+ * Encapsulated authentication/user module for the Racket sandbox.
+ *
+ * Database:
+ *   data/racket-sandbox.sqlite
+ *
+ * Public model:
+ *   RacketSandboxAuth
+ *   RacketSandboxUser
+ *
+ * Outside code should not inspect DB rows directly.
+ */
+
+class RacketSandboxAuthException extends Exception
+{
+}
+
+class RacketSandboxUser
+{
+    private $row;
+
+    public function __construct($row)
+    {
+        $this->row = is_array($row) ? $row : array();
+    }
+
+    public function id()
+    {
+        return (int)($this->row['id'] ?? 0);
+    }
+
+    public function email()
+    {
+        return (string)($this->row['email'] ?? '');
+    }
+
+    public function fullName()
+    {
+        return (string)($this->row['full_name'] ?? '');
+    }
+
+    public function displayName()
+    {
+        $name = $this->fullName();
+        $email = $this->email();
+
+        if ($name !== '' && $email !== '') {
+            return $name . ' <' . $email . '>';
+        }
+
+        if ($name !== '') {
+            return $name;
+        }
+
+        return $email;
+    }
+
+    public function isAdmin()
+    {
+        return (int)($this->row['is_admin'] ?? 0) === 1;
+    }
+
+    public function isEnabled()
+    {
+        return (int)($this->row['is_enabled'] ?? 0) === 1;
+    }
+
+    public function createdAt()
+    {
+        return isset($this->row['created_at']) ? (int)$this->row['created_at'] : null;
+    }
+
+    public function updatedAt()
+    {
+        return isset($this->row['updated_at']) ? (int)$this->row['updated_at'] : null;
+    }
+
+    public function lastLoginAt()
+    {
+        return isset($this->row['last_login_at']) && $this->row['last_login_at'] !== null
+            ? (int)$this->row['last_login_at']
+            : null;
+    }
+
+    public function sessionExpiresAt()
+    {
+        return isset($this->row['session_expires_at']) && $this->row['session_expires_at'] !== null
+            ? (int)$this->row['session_expires_at']
+            : null;
+    }
+
+    public function raw()
+    {
+        return $this->row;
+    }
+}
+
+class RacketSandboxAuth
+{
+    private $db;
+    private $sessionCookieName;
+    private $sessionTtlSeconds;
+
+    public function __construct($dbFile, $options = array())
+    {
+        $dir = dirname($dbFile);
+
+        if (!is_dir($dir)) {
+            if (!mkdir($dir, 0700, true)) {
+                throw new RacketSandboxAuthException('Could not create database directory: ' . $dir);
+            }
+        }
+
+        $this->sessionCookieName = isset($options['cookie_name'])
+            ? (string)$options['cookie_name']
+            : 'rkt_sandbox_session';
+
+        $this->sessionTtlSeconds = isset($options['session_ttl'])
+            ? (int)$options['session_ttl']
+            : 12 * 3600;
+
+        $this->db = new PDO('sqlite:' . $dbFile);
+        $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+        $this->db->exec('PRAGMA journal_mode = WAL');
+        $this->db->exec('PRAGMA busy_timeout = 5000');
+
+        $this->init();
+    }
+
+    private function init()
+    {
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS users (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                email TEXT NOT NULL UNIQUE,
+                full_name TEXT NOT NULL,
+                password_hash TEXT NOT NULL,
+                is_admin INTEGER NOT NULL DEFAULT 0,
+                is_enabled INTEGER NOT NULL DEFAULT 1,
+                created_at INTEGER NOT NULL,
+                updated_at INTEGER NOT NULL,
+                last_login_at INTEGER NULL
+            )'
+        );
+
+        $this->migrateUsersTable();
+
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS auth_sessions (
+                token TEXT PRIMARY KEY,
+                user_id INTEGER NOT NULL,
+                created_at INTEGER NOT NULL,
+                expires_at INTEGER NOT NULL,
+                last_seen_at INTEGER NOT NULL,
+                user_agent TEXT NULL,
+                remote_addr TEXT NULL,
+                FOREIGN KEY(user_id) REFERENCES users(id)
+            )'
+        );
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_auth_sessions_user
+             ON auth_sessions(user_id)'
+        );
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_auth_sessions_expires
+             ON auth_sessions(expires_at)'
+        );
+    }
+
+    private function migrateUsersTable()
+    {
+        $cols = $this->tableColumns('users');
+
+        if (isset($cols['username']) && !isset($cols['email'])) {
+            $this->db->exec('ALTER TABLE users RENAME COLUMN username TO email');
+            $cols = $this->tableColumns('users');
+        }
+
+        if (!isset($cols['full_name'])) {
+            $this->db->exec("ALTER TABLE users ADD COLUMN full_name TEXT NOT NULL DEFAULT ''");
+            $this->db->exec("UPDATE users SET full_name = email WHERE full_name = ''");
+        }
+    }
+
+    private function tableColumns($table)
+    {
+        $stmt = $this->db->query('PRAGMA table_info(' . $table . ')');
+        $cols = array();
+
+        foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
+            $cols[$row['name']] = true;
+        }
+
+        return $cols;
+    }
+
+    public function createUser($email, $fullName, $password, $isAdmin = false, $enabled = true)
+    {
+        $email = $this->safeEmail($email);
+        $fullName = $this->safeFullName($fullName);
+        $this->assertPasswordUsable($password);
+
+        $now = time();
+        $hash = password_hash($password, PASSWORD_DEFAULT);
+
+        if ($hash === false) {
+            throw new RacketSandboxAuthException('Could not hash password.');
+        }
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO users
+             (email, full_name, password_hash, is_admin, is_enabled, created_at, updated_at)
+             VALUES
+             (:email, :full_name, :password_hash, :is_admin, :is_enabled, :created_at, :updated_at)'
+        );
+
+        $stmt->execute(array(
+            ':email' => $email,
+            ':full_name' => $fullName,
+            ':password_hash' => $hash,
+            ':is_admin' => $isAdmin ? 1 : 0,
+            ':is_enabled' => $enabled ? 1 : 0,
+            ':created_at' => $now,
+            ':updated_at' => $now,
+        ));
+
+        return $this->getUserById((int)$this->db->lastInsertId());
+    }
+
+    public function login($email, $password)
+    {
+        $email = $this->safeEmail($email);
+
+        $stmt = $this->db->prepare(
+            'SELECT *
+             FROM users
+             WHERE email = :email'
+        );
+
+        $stmt->execute(array(':email' => $email));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            throw new RacketSandboxAuthException('Invalid email address or password.');
+        }
+
+        if ((int)$row['is_enabled'] !== 1) {
+            throw new RacketSandboxAuthException('This account is disabled.');
+        }
+
+        if (!password_verify($password, $row['password_hash'])) {
+            throw new RacketSandboxAuthException('Invalid email address or password.');
+        }
+
+        if (password_needs_rehash($row['password_hash'], PASSWORD_DEFAULT)) {
+            $this->setPasswordById((int)$row['id'], $password, false);
+        }
+
+        $token = $this->createSession((int)$row['id']);
+        $this->setSessionCookie($token);
+
+        $stmt = $this->db->prepare(
+            'UPDATE users
+             SET last_login_at = :last_login_at
+             WHERE id = :id'
+        );
+
+        $stmt->execute(array(
+            ':last_login_at' => time(),
+            ':id' => (int)$row['id'],
+        ));
+
+        return $this->getUserById((int)$row['id']);
+    }
+
+    public function logout()
+    {
+        $token = $this->cookieToken();
+
+        if ($token !== null) {
+            $this->deleteSession($token);
+        }
+
+        $this->clearSessionCookie();
+    }
+
+    public function currentUser()
+    {
+        $token = $this->cookieToken();
+
+        if ($token === null || !$this->validTokenSyntax($token)) {
+            return null;
+        }
+
+        $stmt = $this->db->prepare(
+            'SELECT
+                 u.id,
+                 u.email,
+                 u.full_name,
+                 u.is_admin,
+                 u.is_enabled,
+                 u.created_at,
+                 u.updated_at,
+                 u.last_login_at,
+                 s.expires_at AS session_expires_at
+             FROM auth_sessions s
+             JOIN users u ON u.id = s.user_id
+             WHERE s.token = :token'
+        );
+
+        $stmt->execute(array(':token' => $token));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            return null;
+        }
+
+        if ((int)$row['is_enabled'] !== 1) {
+            $this->deleteSession($token);
+            return null;
+        }
+
+        if (time() > (int)$row['session_expires_at']) {
+            $this->deleteSession($token);
+            return null;
+        }
+
+        $this->touchSession($token);
+
+        return new RacketSandboxUser($row);
+    }
+
+    public function requireLoginHtml()
+    {
+        $user = $this->currentUser();
+
+        if ($user !== null) {
+            return $user;
+        }
+
+        $this->loginRequiredHtml();
+    }
+
+    public function requireAdminHtml()
+    {
+        $user = $this->requireLoginHtml();
+
+        if ($user->isAdmin()) {
+            return $user;
+        }
+
+        $this->messageHtml(
+            'Not available',
+            'Admin rights are required for this page.'
+        );
+    }
+
+    public function listUsers()
+    {
+        $stmt = $this->db->query(
+            'SELECT
+                 id, email, full_name, is_admin, is_enabled,
+                 created_at, updated_at, last_login_at
+             FROM users
+             ORDER BY email COLLATE NOCASE'
+        );
+
+        $out = array();
+
+        foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
+            $out[] = new RacketSandboxUser($row);
+        }
+
+        return $out;
+    }
+
+    public function getUser($id)
+    {
+        return $this->getUserById($id);
+    }
+
+    public function setAdmin($userId, $isAdmin)
+    {
+        $this->updateUserFlag($userId, 'is_admin', $isAdmin);
+    }
+
+    public function setEnabled($userId, $isEnabled)
+    {
+        $this->updateUserFlag($userId, 'is_enabled', $isEnabled);
+
+        if (!$isEnabled) {
+            $stmt = $this->db->prepare(
+                'DELETE FROM auth_sessions
+                 WHERE user_id = :user_id'
+            );
+            $stmt->execute(array(':user_id' => (int)$userId));
+        }
+    }
+
+    public function updateUser($userId, $email, $fullName)
+    {
+        $userId = (int)$userId;
+        $email = $this->safeEmail($email);
+        $fullName = $this->safeFullName($fullName);
+
+        $stmt = $this->db->prepare(
+            'UPDATE users
+             SET email = :email,
+                 full_name = :full_name,
+                 updated_at = :updated_at
+             WHERE id = :id'
+        );
+
+        $stmt->execute(array(
+            ':email' => $email,
+            ':full_name' => $fullName,
+            ':updated_at' => time(),
+            ':id' => $userId,
+        ));
+
+        return $this->getUserById($userId);
+    }
+
+    public function setPassword($email, $newPassword)
+    {
+        $email = $this->safeEmail($email);
+
+        $stmt = $this->db->prepare(
+            'SELECT id
+             FROM users
+             WHERE email = :email'
+        );
+
+        $stmt->execute(array(':email' => $email));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            throw new RacketSandboxAuthException('Unknown user: ' . $email);
+        }
+
+        $this->setPasswordById((int)$row['id'], $newPassword, true);
+    }
+
+    public function deleteUser($userId)
+    {
+        $userId = (int)$userId;
+
+        $this->db->beginTransaction();
+
+        try {
+            $stmt = $this->db->prepare(
+                'DELETE FROM auth_sessions
+                 WHERE user_id = :user_id'
+            );
+            $stmt->execute(array(':user_id' => $userId));
+
+            $stmt = $this->db->prepare(
+                'DELETE FROM users
+                 WHERE id = :id'
+            );
+            $stmt->execute(array(':id' => $userId));
+
+            $this->db->commit();
+        } catch (Throwable $e) {
+            if ($this->db->inTransaction()) {
+                $this->db->rollBack();
+            }
+
+            throw $e;
+        }
+    }
+
+    public function cleanupSessions()
+    {
+        $stmt = $this->db->prepare(
+            'DELETE FROM auth_sessions
+             WHERE expires_at < :now'
+        );
+
+        $stmt->execute(array(':now' => time()));
+        return $stmt->rowCount();
+    }
+
+    private function getUserById($id)
+    {
+        $stmt = $this->db->prepare(
+            'SELECT
+                 id, email, full_name, is_admin, is_enabled,
+                 created_at, updated_at, last_login_at
+             FROM users
+             WHERE id = :id'
+        );
+
+        $stmt->execute(array(':id' => (int)$id));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            return null;
+        }
+
+        return new RacketSandboxUser($row);
+    }
+
+    private function createSession($userId)
+    {
+        $token = bin2hex(random_bytes(32));
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO auth_sessions
+             (token, user_id, created_at, expires_at, last_seen_at, user_agent, remote_addr)
+             VALUES
+             (:token, :user_id, :created_at, :expires_at, :last_seen_at, :user_agent, :remote_addr)'
+        );
+
+        $stmt->execute(array(
+            ':token' => $token,
+            ':user_id' => (int)$userId,
+            ':created_at' => $now,
+            ':expires_at' => $now + $this->sessionTtlSeconds,
+            ':last_seen_at' => $now,
+            ':user_agent' => $_SERVER['HTTP_USER_AGENT'] ?? null,
+            ':remote_addr' => $_SERVER['REMOTE_ADDR'] ?? null,
+        ));
+
+        return $token;
+    }
+
+    private function touchSession($token)
+    {
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'UPDATE auth_sessions
+             SET last_seen_at = :last_seen_at,
+                 expires_at = :expires_at
+             WHERE token = :token'
+        );
+
+        $stmt->execute(array(
+            ':last_seen_at' => $now,
+            ':expires_at' => $now + $this->sessionTtlSeconds,
+            ':token' => $token,
+        ));
+    }
+
+    private function deleteSession($token)
+    {
+        $stmt = $this->db->prepare(
+            'DELETE FROM auth_sessions
+             WHERE token = :token'
+        );
+
+        $stmt->execute(array(':token' => $token));
+    }
+
+    private function setPasswordById($userId, $newPassword, $deleteSessions)
+    {
+        $this->assertPasswordUsable($newPassword);
+
+        $hash = password_hash($newPassword, PASSWORD_DEFAULT);
+
+        if ($hash === false) {
+            throw new RacketSandboxAuthException('Could not hash password.');
+        }
+
+        $stmt = $this->db->prepare(
+            'UPDATE users
+             SET password_hash = :password_hash,
+                 updated_at = :updated_at
+             WHERE id = :id'
+        );
+
+        $stmt->execute(array(
+            ':password_hash' => $hash,
+            ':updated_at' => time(),
+            ':id' => (int)$userId,
+        ));
+
+        if ($deleteSessions) {
+            $stmt = $this->db->prepare(
+                'DELETE FROM auth_sessions
+                 WHERE user_id = :user_id'
+            );
+
+            $stmt->execute(array(':user_id' => (int)$userId));
+        }
+    }
+
+    private function updateUserFlag($userId, $column, $value)
+    {
+        if ($column !== 'is_admin' && $column !== 'is_enabled') {
+            throw new RacketSandboxAuthException('Invalid flag column.');
+        }
+
+        $stmt = $this->db->prepare(
+            'UPDATE users
+             SET ' . $column . ' = :value,
+                 updated_at = :updated_at
+             WHERE id = :id'
+        );
+
+        $stmt->execute(array(
+            ':value' => $value ? 1 : 0,
+            ':updated_at' => time(),
+            ':id' => (int)$userId,
+        ));
+    }
+
+    private function cookieToken()
+    {
+        $token = $_COOKIE[$this->sessionCookieName] ?? null;
+
+        if (!is_string($token) || !$this->validTokenSyntax($token)) {
+            return null;
+        }
+
+        return $token;
+    }
+
+    private function setSessionCookie($token)
+    {
+        $secure = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off');
+
+        setcookie($this->sessionCookieName, $token, array(
+            'expires' => time() + $this->sessionTtlSeconds,
+            'path' => '/',
+            'secure' => $secure,
+            'httponly' => true,
+            'samesite' => 'Lax',
+        ));
+    }
+
+    private function clearSessionCookie()
+    {
+        $secure = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off');
+
+        setcookie($this->sessionCookieName, '', array(
+            'expires' => time() - 3600,
+            'path' => '/',
+            'secure' => $secure,
+            'httponly' => true,
+            'samesite' => 'Lax',
+        ));
+    }
+
+    private function validTokenSyntax($token)
+    {
+        return is_string($token) && preg_match('/^[a-f0-9]{64}$/', $token);
+    }
+
+    private function safeEmail($email)
+    {
+        $email = strtolower(trim((string)$email));
+
+        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
+            throw new RacketSandboxAuthException('Invalid email address.');
+        }
+
+        if (strlen($email) > 160) {
+            throw new RacketSandboxAuthException('Email address is too long.');
+        }
+
+        return $email;
+    }
+
+    private function safeFullName($fullName)
+    {
+        $fullName = trim((string)$fullName);
+
+        if ($fullName === '') {
+            throw new RacketSandboxAuthException('Full name is required.');
+        }
+
+        if (strlen($fullName) > 160) {
+            throw new RacketSandboxAuthException('Full name is too long.');
+        }
+
+        return $fullName;
+    }
+
+    private function assertPasswordUsable($password)
+    {
+        if (!is_string($password) || strlen($password) < 10) {
+            throw new RacketSandboxAuthException('Password must be at least 10 characters.');
+        }
+    }
+
+    private function loginRequiredHtml()
+    {
+        $this->messageHtml(
+            'Login required',
+            'Please log in to continue.',
+            '<p><a href="/login.php">Login</a></p>'
+        );
+    }
+
+    private function messageHtml($title, $message, $extra = '')
+    {
+        http_response_code(200);
+        header('Content-Type: text/html; charset=utf-8');
+
+        echo '<!doctype html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<title>' . htmlspecialchars($title, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8') . '</title>
+</head>
+<body>
+<h1>' . htmlspecialchars($title, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8') . '</h1>
+<p>' . htmlspecialchars($message, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8') . '</p>
+' . $extra . '
+</body>
+</html>';
+        exit;
+    }
+}
diff --git a/b64parts.php b/b64parts.php
new file mode 100644
index 0000000..192d39f
--- /dev/null
+++ b/b64parts.php
@@ -0,0 +1,264 @@
+<?php
+/*
+ * b64parts.php
+ *
+ * Zet een gegeven bestand, bijvoorbeeld een zip, om naar base64-parts.
+ *
+ * Regels:
+ *   - Inputbestand mag binary zijn.
+ *   - Output-parts zijn plain base64 tekst.
+ *   - Geen chunk_split; dus geen extra newline-overhead.
+ *   - Max part size geldt voor de base64-tekst, niet voor de binary input.
+ *
+ * Voorbeeld:
+ *
+ *   require_once __DIR__ . '/b64parts.php';
+ *
+ *   $parts = new Base64Parts(__DIR__ . '/data');
+ *   $manifest = $parts->splitFile(
+ *       __DIR__ . '/data/html-parsing.zip',
+ *       'html-parsing'
+ *   );
+ *
+ *   print_r($manifest);
+ */
+
+class Base64PartsException extends Exception
+{
+}
+
+class Base64Parts
+{
+    private $dataDir;
+    private $maxBase64PartBytes;
+
+    public function __construct($dataDir, $maxBase64PartBytes = null)
+    {
+        $this->dataDir = rtrim((string)$dataDir, '/');
+
+        /*
+         * Max grootte van de base64-text per part.
+         * Houd dit op 2 MiB tenzij je fetcher kleiner nodig heeft.
+         */
+        $this->maxBase64PartBytes = $maxBase64PartBytes === null
+            ? 2 * 1024 * 1024
+            : (int)$maxBase64PartBytes;
+
+        if ($this->maxBase64PartBytes < 1024) {
+            throw new Base64PartsException('maxBase64PartBytes is te klein.');
+        }
+    }
+
+    public function splitFile($sourceFile, $name, $clearOldParts = true)
+    {
+        $sourceFile = (string)$sourceFile;
+        $name = $this->safeName($name);
+
+        if (!is_file($sourceFile) || !is_readable($sourceFile)) {
+            throw new Base64PartsException('Bronbestand ontbreekt of is niet leesbaar: ' . $sourceFile);
+        }
+
+        $this->ensureDataDir();
+
+        if ($clearOldParts) {
+            $this->removeParts($name);
+        }
+
+        /*
+         * Base64 maakt van 3 binary bytes precies 4 tekstbytes.
+         * Door de binary chunk op een veelvoud van 3 te houden, krijgen
+         * alle niet-laatste parts een nette base64-lengte zonder padding.
+         */
+        $maxBinaryChunkBytes = intdiv($this->maxBase64PartBytes, 4) * 3;
+
+        if ($maxBinaryChunkBytes < 3) {
+            throw new Base64PartsException('Berekende binary chunk size is ongeldig.');
+        }
+
+        $in = fopen($sourceFile, 'rb');
+
+        if ($in === false) {
+            throw new Base64PartsException('Kan bronbestand niet openen: ' . $sourceFile);
+        }
+
+        $parts = array();
+        $nr = 1;
+        $totalBinaryBytes = 0;
+        $totalBase64Bytes = 0;
+
+        while (!feof($in)) {
+            $bin = fread($in, $maxBinaryChunkBytes);
+
+            if ($bin === false) {
+                fclose($in);
+                throw new Base64PartsException('Fout bij lezen van: ' . $sourceFile);
+            }
+
+            if ($bin === '') {
+                break;
+            }
+
+            $b64 = base64_encode($bin);
+
+            if (strlen($b64) > $this->maxBase64PartBytes) {
+                fclose($in);
+                throw new Base64PartsException('Interne fout: base64 part is groter dan maximum.');
+            }
+
+            $partNumber = sprintf('%06d', $nr);
+            $partFile = $this->partFile($name, $partNumber);
+
+            if (file_put_contents($partFile, $b64, LOCK_EX) === false) {
+                fclose($in);
+                throw new Base64PartsException('Kan part niet schrijven: ' . $partFile);
+            }
+
+            $binaryBytes = strlen($bin);
+            $base64Bytes = strlen($b64);
+
+            $parts[] = array(
+                'number'       => $partNumber,
+                'file'         => $partFile,
+                'basename'     => basename($partFile),
+                'binary_bytes' => $binaryBytes,
+                'base64_bytes' => $base64Bytes,
+            );
+
+            $totalBinaryBytes += $binaryBytes;
+            $totalBase64Bytes += $base64Bytes;
+            $nr++;
+        }
+
+        fclose($in);
+
+        if (count($parts) === 0) {
+            throw new Base64PartsException('Bronbestand is leeg: ' . $sourceFile);
+        }
+
+        $manifest = array(
+            'name'               => $name,
+            'source_file'        => $sourceFile,
+            'source_bytes'       => filesize($sourceFile),
+            'source_sha256'      => hash_file('sha256', $sourceFile),
+            'max_base64_bytes'   => $this->maxBase64PartBytes,
+            'binary_chunk_bytes' => $maxBinaryChunkBytes,
+            'part_count'         => count($parts),
+            'total_binary_bytes' => $totalBinaryBytes,
+            'total_base64_bytes' => $totalBase64Bytes,
+            'parts'              => $parts,
+            'created_at'         => gmdate('c'),
+        );
+
+        $manifestFile = $this->manifestFile($name);
+
+        if (file_put_contents(
+            $manifestFile,
+            json_encode($manifest, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . "\n",
+            LOCK_EX
+        ) === false) {
+            throw new Base64PartsException('Kan manifest niet schrijven: ' . $manifestFile);
+        }
+
+        $manifest['manifest_file'] = $manifestFile;
+
+        return $manifest;
+    }
+
+    public function readPart($name, $partNumber)
+    {
+        $name = $this->safeName($name);
+
+        if (!preg_match('/^[0-9]{6}$/', (string)$partNumber)) {
+            throw new Base64PartsException('Ongeldig partnummer: ' . $partNumber);
+        }
+
+        $file = $this->partFile($name, $partNumber);
+
+        if (!is_file($file) || !is_readable($file)) {
+            throw new Base64PartsException('Part ontbreekt of is niet leesbaar: ' . $file);
+        }
+
+        $txt = file_get_contents($file);
+
+        if ($txt === false) {
+            throw new Base64PartsException('Kan part niet lezen: ' . $file);
+        }
+
+        return $txt;
+    }
+
+    public function loadManifest($name)
+    {
+        $name = $this->safeName($name);
+        $file = $this->manifestFile($name);
+
+        if (!is_file($file) || !is_readable($file)) {
+            throw new Base64PartsException('Manifest ontbreekt: ' . $file);
+        }
+
+        $raw = file_get_contents($file);
+
+        if ($raw === false) {
+            throw new Base64PartsException('Kan manifest niet lezen: ' . $file);
+        }
+
+        $json = json_decode($raw, true);
+
+        if (!is_array($json)) {
+            throw new Base64PartsException('Manifest is geen geldige JSON: ' . $file);
+        }
+
+        return $json;
+    }
+
+    public function removeParts($name)
+    {
+        $name = $this->safeName($name);
+
+        foreach (glob($this->dataDir . '/' . $name . '.part.*.b64') ?: array() as $file) {
+            if (is_file($file)) {
+                @unlink($file);
+            }
+        }
+
+        $manifest = $this->manifestFile($name);
+
+        if (is_file($manifest)) {
+            @unlink($manifest);
+        }
+    }
+
+    private function ensureDataDir()
+    {
+        if (!is_dir($this->dataDir)) {
+            if (!mkdir($this->dataDir, 0755, true)) {
+                throw new Base64PartsException('Kan data directory niet maken: ' . $this->dataDir);
+            }
+        }
+
+        if (!is_writable($this->dataDir)) {
+            throw new Base64PartsException('Data directory is niet schrijfbaar: ' . $this->dataDir);
+        }
+    }
+
+    private function safeName($name)
+    {
+        $name = (string)$name;
+
+        if (!preg_match('/^[A-Za-z0-9_.+-]+$/', $name)) {
+            throw new Base64PartsException('Ongeldige naam: ' . $name);
+        }
+
+        return $name;
+    }
+
+    private function partFile($name, $partNumber)
+    {
+        return $this->dataDir . '/' . $name . '.part.' . $partNumber . '.b64';
+    }
+
+    private function manifestFile($name)
+    {
+        return $this->dataDir . '/' . $name . '.parts.json';
+    }
+}
\ No newline at end of file
diff --git a/base64config.php b/base64config.php
new file mode 100644
index 0000000..3324be5
--- /dev/null
+++ b/base64config.php
@@ -0,0 +1,69 @@
+<?php
+/*
+ * Shared configuration for maximum base64 payload sizes.
+ */
+
+define('BASE64_CHUNK_CONFIG_FILE', __DIR__ . '/config/base64-chunks.php');
+
+function base64_chunk_defaults()
+{
+    return array(
+        'racket_zip_max_base64_kb' => 8192,
+        'package_zip_max_base64_kb' => 2048,
+    );
+}
+
+function load_base64_chunk_config()
+{
+    $defaults = base64_chunk_defaults();
+    $config = is_file(BASE64_CHUNK_CONFIG_FILE)
+        ? require BASE64_CHUNK_CONFIG_FILE
+        : array();
+
+    if (!is_array($config)) {
+        $config = array();
+    }
+
+    foreach ($defaults as $key => $default) {
+        $value = (int)($config[$key] ?? $default);
+        $config[$key] = $value > 0 ? $value : $default;
+    }
+
+    return array_intersect_key($config, $defaults);
+}
+
+function save_base64_chunk_config($config)
+{
+    $defaults = base64_chunk_defaults();
+    $clean = array();
+
+    foreach ($defaults as $key => $default) {
+        $value = (int)($config[$key] ?? $default);
+
+        if ($value < 1) {
+            throw new InvalidArgumentException('Base64 chunk size must be at least 1 KiB.');
+        }
+
+        $clean[$key] = $value;
+    }
+
+    $php = "<?php\n" .
+        "/*\n" .
+        " * Maximale grootte van base64-payloads, in KiB.\n" .
+        " *\n" .
+        " * 1 KiB = 1024 bytes. De splitter rondt intern waar nodig naar beneden af\n" .
+        " * zodat de binaire chunks netjes naar base64 omgezet kunnen worden.\n" .
+        " */\n\n" .
+        "return " . var_export($clean, true) . ";\n";
+
+    $tmp = BASE64_CHUNK_CONFIG_FILE . '.tmp';
+
+    if (file_put_contents($tmp, $php, LOCK_EX) === false) {
+        throw new RuntimeException('Could not write temporary base64 chunk config.');
+    }
+
+    if (!rename($tmp, BASE64_CHUNK_CONFIG_FILE)) {
+        @unlink($tmp);
+        throw new RuntimeException('Could not replace base64 chunk config.');
+    }
+}
diff --git a/bootstrap-prompt.js b/bootstrap-prompt.js
new file mode 100644
index 0000000..d313444
--- /dev/null
+++ b/bootstrap-prompt.js
@@ -0,0 +1,45 @@
+(function () {
+    'use strict';
+
+    function byId(id) {
+        return document.getElementById(id);
+    }
+
+    function renderPrompt(data, select, output) {
+        const selectedId = select.value;
+        const prompt = (data.prompts || []).find(function (item) {
+            return String(item.id) === String(selectedId);
+        });
+
+        if (!prompt) {
+            output.value = '';
+            return;
+        }
+
+        output.value = String(prompt.content || '').split('{{bootstrap-racket-link}}').join(data.link || '');
+    }
+
+    document.addEventListener('DOMContentLoaded', function () {
+        const dataEl = byId('bootstrapPromptData');
+        const select = byId('bootstrapPromptSelect');
+        const output = byId('bootstrapPromptOutput');
+
+        if (!dataEl || !select || !output) {
+            return;
+        }
+
+        let data = { link: '', prompts: [] };
+
+        try {
+            data = JSON.parse(dataEl.textContent || '{}');
+        } catch (e) {
+            data = { link: '', prompts: [] };
+        }
+
+        select.addEventListener('change', function () {
+            renderPrompt(data, select, output);
+        });
+
+        renderPrompt(data, select, output);
+    });
+}());
diff --git a/clipboard.js b/clipboard.js
new file mode 100644
index 0000000..20fc4fc
--- /dev/null
+++ b/clipboard.js
@@ -0,0 +1,56 @@
+(function () {
+    'use strict';
+
+    function fallbackCopy(text) {
+        const input = document.createElement('textarea');
+        input.value = text;
+        input.setAttribute('readonly', 'readonly');
+        input.style.position = 'fixed';
+        input.style.left = '-9999px';
+        document.body.appendChild(input);
+        input.select();
+
+        try {
+            document.execCommand('copy');
+        } finally {
+            document.body.removeChild(input);
+        }
+    }
+
+    function copyText(text) {
+        if (navigator.clipboard && navigator.clipboard.writeText) {
+            return navigator.clipboard.writeText(text);
+        }
+
+        fallbackCopy(text);
+        return Promise.resolve();
+    }
+
+    function showCopied(button) {
+        const original = button.dataset.copyLabel || button.textContent;
+        const copied = button.dataset.copiedLabel || 'Copied';
+
+        button.textContent = copied;
+        window.setTimeout(function () {
+            button.textContent = original;
+        }, 1400);
+    }
+
+    document.addEventListener('DOMContentLoaded', function () {
+        document.querySelectorAll('.js-copy-button').forEach(function (button) {
+            button.addEventListener('click', function () {
+                let text = button.dataset.copyText || '';
+                const targetId = button.dataset.copyTarget || '';
+                const target = targetId ? document.getElementById(targetId) : null;
+
+                if (target) {
+                    text = target.value || target.textContent || '';
+                }
+
+                copyText(text).then(function () {
+                    showCopied(button);
+                });
+            });
+        });
+    });
+}());
diff --git a/config.php b/config.php
new file mode 100644
index 0000000..94f1eb4
--- /dev/null
+++ b/config.php
@@ -0,0 +1,349 @@
+<?php
+/*
+ * config.php
+ *
+ * Admin application configuration.
+ */
+
+require_once __DIR__ . '/auth.php';
+require_once __DIR__ . '/header.php';
+require_once __DIR__ . '/languagestore.php';
+require_once __DIR__ . '/nexttoken.php';
+require_once __DIR__ . '/usersettings.php';
+require_once __DIR__ . '/base64config.php';
+require_once __DIR__ . '/racketzip.php';
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+$DB_FILE = __DIR__ . '/data/racket-sandbox.sqlite';
+
+$auth = new RacketSandboxAuth($DB_FILE);
+$languageStore = new LanguageStore($DB_FILE);
+$tokens = new NextTokenStore($DB_FILE);
+$userSettings = new UserSettingsStore($DB_FILE);
+$currentUser = $auth->requireAdminHtml();
+
+$message = '';
+$error = '';
+$base64ChunkConfig = load_base64_chunk_config();
+$localTimezone = new DateTimeZone('Europe/Amsterdam');
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function t($key, $fallback = null)
+{
+    global $languageStore, $language;
+
+    return $languageStore->translate($key, $language, $fallback);
+}
+
+function post_value($name, $default = '')
+{
+    return $_POST[$name] ?? $default;
+}
+
+function resolve_user_language($userSettings, $userId, $allowedLanguages)
+{
+    $language = isset($_GET['lang'])
+        ? (string)$_GET['lang']
+        : (string)$userSettings->get($userId, 'language', 'en');
+
+    if (!in_array($language, $allowedLanguages, true)) {
+        $language = 'en';
+    }
+
+    $userSettings->set($userId, 'language', $language);
+
+    return $language;
+}
+
+function base64_binary_chunk_bytes_for_kib($kib)
+{
+    return racket_zip_binary_chunk_bytes_for_base64_kib($kib);
+}
+
+function format_token_time($timestamp)
+{
+    global $localTimezone;
+
+    $time = (new DateTimeImmutable('@' . (int)$timestamp))->setTimezone($localTimezone);
+
+    return $time->format('Y-m-d H:i:s T');
+}
+
+function token_status_class($token)
+{
+    return time() <= (int)($token['expires_at'] ?? 0)
+        ? 'token-valid'
+        : 'token-expired';
+}
+
+$language = resolve_user_language(
+    $userSettings,
+    $currentUser->id(),
+    $languageStore->supportedLanguages()
+);
+
+$languageStore->seedDefaults(array(
+    'app.title' => array('en' => 'Racket sandbox', 'nl' => 'Racket sandbox'),
+    'app.manage_prompts' => array('en' => 'Manage prompts', 'nl' => 'Prompts beheren'),
+    'app.user_management' => array('en' => 'User management', 'nl' => 'Gebruikersbeheer'),
+    'app.configuration' => array('en' => 'Configuration', 'nl' => 'Configuratie'),
+    'app.logout' => array('en' => 'Logout', 'nl' => 'Uitloggen'),
+    'app.language' => array('en' => 'Language', 'nl' => 'Taal'),
+    'app.logged_in_as' => array('en' => 'Logged in as:', 'nl' => 'Ingelogd als:'),
+    'app.admin' => array('en' => 'Admin', 'nl' => 'Admin'),
+    'app.back_to_sandbox' => array('en' => 'Back to Racket sandbox', 'nl' => 'Terug naar Racket sandbox'),
+    'app.download_settings' => array('en' => 'Download settings', 'nl' => 'Downloadinstellingen'),
+    'app.maintenance' => array('en' => 'Maintenance', 'nl' => 'Onderhoud'),
+    'app.next_tokens' => array('en' => 'Next tokens', 'nl' => 'Next-tokens'),
+    'app.current_next_tokens' => array('en' => 'Next tokens', 'nl' => 'Next-tokens'),
+    'app.token' => array('en' => 'Token', 'nl' => 'Token'),
+    'app.created_at' => array('en' => 'Created at', 'nl' => 'Aangemaakt op'),
+    'app.expires_at' => array('en' => 'Expires at', 'nl' => 'Verloopt op'),
+    'app.no_current_next_tokens' => array('en' => 'No next tokens.', 'nl' => 'Geen next-tokens.'),
+    'app.remove_expired_tokens' => array('en' => 'Remove expired next tokens', 'nl' => 'Verlopen next-tokens verwijderen'),
+    'app.racket_zip_chunk_kb' => array('en' => 'Racket installation max base64 chunk size (KiB)', 'nl' => 'Maximale base64-chunkgrootte Racket-installatie (KiB)'),
+    'app.package_zip_chunk_kb' => array('en' => 'Package/module max base64 chunk size (KiB)', 'nl' => 'Maximale base64-chunkgrootte packages/modules (KiB)'),
+    'app.save_configuration' => array('en' => 'Save configuration', 'nl' => 'Configuratie opslaan'),
+    'app.configuration_saved' => array('en' => 'Configuration saved.', 'nl' => 'Configuratie opgeslagen.'),
+    'app.racket_parts_regenerated' => array('en' => 'Racket installation parts regenerated:', 'nl' => 'Racket-installatie parts opnieuw gemaakt:'),
+    'app.chunk_size_hint_v2' => array(
+        'en' => 'Values are maximum base64 payload sizes in KiB. A 6144 KiB binary chunk becomes 8192 KiB base64. Racket installation parts are regenerated when this configuration is saved.',
+        'nl' => 'Waarden zijn maximale base64-payloadgroottes in KiB. Een binaire chunk van 6144 KiB wordt 8192 KiB base64. Racket-installatie parts worden opnieuw gemaakt wanneer deze configuratie wordt opgeslagen.',
+    ),
+    'app.effective_binary_chunk' => array('en' => 'Effective binary chunk', 'nl' => 'Effectieve binaire chunk'),
+    'app.racket_zip_source' => array('en' => 'Racket installation source', 'nl' => 'Bronbestand Racket-installatie'),
+    'app.racket_parts' => array('en' => 'Racket installation parts', 'nl' => 'Racket-installatie parts'),
+    'app.racket_parts_current' => array('en' => 'current', 'nl' => 'actueel'),
+    'app.racket_parts_missing' => array('en' => 'missing or outdated; save configuration to regenerate', 'nl' => 'ontbreken of verouderd; sla configuratie op om opnieuw te maken'),
+    'app.expired_tokens_removed' => array('en' => 'Expired next tokens removed:', 'nl' => 'Verlopen next-tokens verwijderd:'),
+    'app.cleanup_help' => array(
+        'en' => 'Expired links should return an outdated information message to the AI agent. Cleanup only removes old token rows from SQLite.',
+        'nl' => 'Verlopen links moeten een melding over verouderde informatie aan de AI-agent teruggeven. Opruimen verwijdert alleen oude tokenrijen uit SQLite.'
+    ),
+));
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    $action = post_value('action');
+
+    try {
+        if ($action === 'logout') {
+            $auth->logout();
+            header('Location: /login.php');
+            exit;
+        } elseif ($action === 'update_config') {
+            save_base64_chunk_config(array(
+                'racket_zip_max_base64_kb' => post_value('racket_zip_max_base64_kb'),
+                'package_zip_max_base64_kb' => post_value('package_zip_max_base64_kb'),
+            ));
+            $base64ChunkConfig = load_base64_chunk_config();
+            $manifest = split_racket_zip_parts($base64ChunkConfig['racket_zip_max_base64_kb']);
+            $message = t('app.configuration_saved', 'Configuration saved.') . ' ' .
+                t('app.racket_parts_regenerated', 'Racket installation parts regenerated:') . ' ' .
+                (int)$manifest['part_count'];
+        } elseif ($action === 'cleanup_tokens') {
+            $deleted = $tokens->cleanup();
+            $message = t('app.expired_tokens_removed', 'Expired next tokens removed:') . ' ' . $deleted;
+        }
+    } catch (Throwable $e) {
+        $error = $e->getMessage();
+    }
+}
+
+$racketPartsManifest = null;
+$racketPartsCurrent = false;
+
+try {
+    $racketPartsManifest = load_racket_zip_parts_manifest();
+    $racketPartsCurrent = racket_zip_parts_current(
+        $racketPartsManifest,
+        $base64ChunkConfig['racket_zip_max_base64_kb']
+    );
+} catch (Throwable $e) {
+    $racketPartsManifest = null;
+    $racketPartsCurrent = false;
+}
+
+if (!$racketPartsCurrent && is_file(RACKET_ZIP_FILE) && is_readable(RACKET_ZIP_FILE)) {
+    try {
+        $racketPartsManifest = split_racket_zip_parts($base64ChunkConfig['racket_zip_max_base64_kb']);
+        $racketPartsCurrent = true;
+
+        if ($message === '') {
+            $message = t('app.racket_parts_regenerated', 'Racket installation parts regenerated:') . ' ' .
+                (int)$racketPartsManifest['part_count'];
+        }
+    } catch (Throwable $e) {
+        if ($error === '') {
+            $error = $e->getMessage();
+        }
+    }
+}
+
+$headerLanguages = array();
+
+$currentNextTokens = array();
+
+try {
+    $currentNextTokens = $tokens->tokens();
+} catch (Throwable $e) {
+    if ($error === '') {
+        $error = $e->getMessage();
+    }
+}
+
+foreach ($languageStore->supportedLanguages() as $lang) {
+    $headerLanguages[$lang] = $languageStore->languageLabel($lang);
+}
+
+$styleVersion = @filemtime(__DIR__ . '/styles.css') ?: time();
+
+header('Content-Type: text/html; charset=utf-8');
+?>
+<!doctype html>
+<html lang="<?= h($language) ?>">
+<head>
+<meta charset="utf-8">
+<title><?= h(t('app.configuration', 'Configuration')) ?></title>
+<link rel="stylesheet" href="/styles.css?v=<?= h($styleVersion) ?>">
+</head>
+<body>
+
+<div class="page">
+
+<?php
+render_app_header(array(
+    'title' => t('app.configuration', 'Configuration'),
+    'nav_items' => array(
+        array('label' => t('app.back_to_sandbox', 'Back to Racket sandbox'), 'url' => '/?lang=' . rawurlencode($language)),
+        array(
+            'label' => t('app.manage_prompts', 'Manage prompts'),
+            'url' => '/prompts?lang=' . rawurlencode($language),
+            'separator_before' => true,
+        ),
+        array(
+            'label' => t('app.user_management', 'User management'),
+            'url' => '/users?lang=' . rawurlencode($language),
+            'separator_before' => true,
+        ),
+        array(
+            'label' => t('app.configuration', 'Configuration'),
+            'url' => '/admin-config?lang=' . rawurlencode($language),
+            'active' => true,
+            'separator_before' => true,
+        ),
+    ),
+    'user' => $currentUser,
+    'user_prefix' => t('app.logged_in_as', 'Logged in as:'),
+    'admin_label' => t('app.admin', 'Admin'),
+    'language_label' => t('app.language', 'Language'),
+    'language' => $language,
+    'languages' => $headerLanguages,
+    'language_action' => '/admin-config',
+    'logout_action' => '/admin-config?lang=' . rawurlencode($language),
+    'logout_label' => t('app.logout', 'Logout'),
+    'message' => $message,
+    'error' => $error,
+));
+?>
+
+<main class="page-main dashboard-main">
+
+<section class="panel">
+<h2><?= h(t('app.download_settings', 'Download settings')) ?></h2>
+
+<form method="post" action="/admin-config?lang=<?= h($language) ?>" class="admin-form-grid">
+<input type="hidden" name="action" value="update_config">
+<label>
+<?= h(t('app.racket_zip_chunk_kb', 'Racket installation max base64 chunk size (KiB)')) ?><br>
+<input type="number" name="racket_zip_max_base64_kb" min="1" step="1" value="<?= h($base64ChunkConfig['racket_zip_max_base64_kb']) ?>" required>
+</label>
+<label>
+<?= h(t('app.package_zip_chunk_kb', 'Package/module max base64 chunk size (KiB)')) ?><br>
+<input type="number" name="package_zip_max_base64_kb" min="1" step="1" value="<?= h($base64ChunkConfig['package_zip_max_base64_kb']) ?>" required>
+</label>
+<button type="submit"><?= h(t('app.save_configuration', 'Save configuration')) ?></button>
+</form>
+
+<p class="small"><?= h(t('app.chunk_size_hint_v2', 'Values are maximum base64 payload sizes in KiB. A 6144 KiB binary chunk becomes 8192 KiB base64. Racket installation parts are regenerated when this configuration is saved.')) ?></p>
+
+<table>
+<tr>
+<th><?= h(t('app.racket_zip_chunk_kb', 'Racket installation max base64 chunk size (KiB)')) ?></th>
+<td><code><?= h($base64ChunkConfig['racket_zip_max_base64_kb']) ?></code> KiB</td>
+<td><?= h(t('app.effective_binary_chunk', 'Effective binary chunk')) ?>: <code><?= h(base64_binary_chunk_bytes_for_kib($base64ChunkConfig['racket_zip_max_base64_kb'])) ?></code> bytes</td>
+</tr>
+<tr>
+<th><?= h(t('app.package_zip_chunk_kb', 'Package/module max base64 chunk size (KiB)')) ?></th>
+<td><code><?= h($base64ChunkConfig['package_zip_max_base64_kb']) ?></code> KiB</td>
+<td><?= h(t('app.effective_binary_chunk', 'Effective binary chunk')) ?>: <code><?= h(base64_binary_chunk_bytes_for_kib($base64ChunkConfig['package_zip_max_base64_kb'])) ?></code> bytes</td>
+</tr>
+<tr>
+<th><?= h(t('app.racket_zip_source', 'Racket installation source')) ?></th>
+<td><code>config/racket.zip</code></td>
+<td><code><?= h(is_file(RACKET_ZIP_FILE) ? (string)filesize(RACKET_ZIP_FILE) : '0') ?></code> bytes</td>
+</tr>
+<tr>
+<th><?= h(t('app.racket_parts', 'Racket installation parts')) ?></th>
+<td><code><?= h((string)($racketPartsManifest['part_count'] ?? 0)) ?></code></td>
+<td>
+<?php if ($racketPartsCurrent): ?>
+<?= h(t('app.racket_parts_current', 'current')) ?>,
+<?= h((string)($racketPartsManifest['created_at'] ?? '')) ?>
+<?php else: ?>
+<?= h(t('app.racket_parts_missing', 'missing or outdated; save configuration to regenerate')) ?>
+<?php endif; ?>
+</td>
+</tr>
+</table>
+</section>
+
+<section class="panel">
+<h2><?= h(t('app.maintenance', 'Maintenance')) ?></h2>
+
+<fieldset>
+<legend><?= h(t('app.next_tokens', 'Next tokens')) ?></legend>
+
+<form method="post" action="/admin-config?lang=<?= h($language) ?>">
+<input type="hidden" name="action" value="cleanup_tokens">
+<button type="submit"><?= h(t('app.remove_expired_tokens', 'Remove expired next tokens')) ?></button>
+</form>
+
+<p class="small">
+<?= h(t('app.cleanup_help', 'Expired links should return an outdated information message to the AI agent. Cleanup only removes old token rows from SQLite.')) ?>
+</p>
+
+<h3><?= h(t('app.current_next_tokens', 'Current next tokens')) ?></h3>
+
+<?php if (count($currentNextTokens) > 0): ?>
+<table>
+<tr>
+<th><?= h(t('app.token', 'Token')) ?></th>
+<th><?= h(t('app.created_at', 'Created at')) ?></th>
+<th><?= h(t('app.expires_at', 'Expires at')) ?></th>
+</tr>
+<?php foreach ($currentNextTokens as $nextToken): ?>
+<tr class="<?= h(token_status_class($nextToken)) ?>">
+<td><code><?= h($nextToken['token'] ?? '') ?></code></td>
+<td><?= h(format_token_time($nextToken['created_at'] ?? 0)) ?></td>
+<td><?= h(format_token_time($nextToken['expires_at'] ?? 0)) ?></td>
+</tr>
+<?php endforeach; ?>
+</table>
+<?php else: ?>
+<p class="small"><?= h(t('app.no_current_next_tokens', 'No current next tokens.')) ?></p>
+<?php endif; ?>
+</fieldset>
+</section>
+
+</main>
+</div>
+</body>
+</html>
diff --git a/config/apikey.cfg b/config/apikey.cfg
new file mode 100644
index 0000000..c2c46ac
--- /dev/null
+++ b/config/apikey.cfg
@@ -0,0 +1 @@
+flfadrdeyc.yvtpmoyjm.gthfkqbrf.kyhhvikcv
diff --git a/config/base64-chunks.php b/config/base64-chunks.php
new file mode 100644
index 0000000..e8e1d0e
--- /dev/null
+++ b/config/base64-chunks.php
@@ -0,0 +1,12 @@
+<?php
+/*
+ * Maximale grootte van base64-payloads, in KiB.
+ *
+ * 1 KiB = 1024 bytes. De splitter rondt intern waar nodig naar beneden af
+ * zodat de binaire chunks netjes naar base64 omgezet kunnen worden.
+ */
+
+return array (
+  'racket_zip_max_base64_kb' => 10240,
+  'package_zip_max_base64_kb' => 2048,
+);
diff --git a/config/index.php b/config/index.php
new file mode 100644
index 0000000..d99fbed
--- /dev/null
+++ b/config/index.php
@@ -0,0 +1,2 @@
+<?php
+require __DIR__ . '/../config.php';
diff --git a/config/next-token-words.php b/config/next-token-words.php
new file mode 100644
index 0000000..fe2e978
--- /dev/null
+++ b/config/next-token-words.php
@@ -0,0 +1,93 @@
+<?php
+
+function expand_next_token_words($baseWords, $modifiers, $targetCount)
+{
+    $out = array();
+
+    foreach ($baseWords as $word) {
+        $out[$word] = true;
+    }
+
+    foreach ($modifiers as $modifier) {
+        foreach ($baseWords as $word) {
+            $out[$modifier . '-' . $word] = true;
+
+            if (count($out) >= $targetCount) {
+                return array_slice(array_keys($out), 0, $targetCount);
+            }
+        }
+    }
+
+    return array_slice(array_keys($out), 0, $targetCount);
+}
+
+$englishAdjectives = array(
+    'agile', 'amber', 'brave', 'bright', 'bouncy', 'calm',
+    'clever', 'cosmic', 'crisp', 'curious', 'dapper', 'daring',
+    'dreamy', 'eager', 'electric', 'fancy', 'fizzy', 'gentle',
+    'glowing', 'golden', 'happy', 'humble', 'jolly', 'jazzy',
+    'kind', 'lively', 'lucky', 'mighty', 'mellow', 'nimble',
+    'noble', 'peppy', 'plucky', 'polite', 'proud', 'quick',
+    'quiet', 'radiant', 'rapid', 'shiny', 'silky', 'snappy',
+    'sparkly', 'steady', 'sunny', 'tidy', 'tiny', 'valiant',
+    'velvet', 'vivid', 'warm', 'witty', 'zesty', 'brisk',
+    'cheery', 'deft', 'fresh', 'neat', 'smart', 'swift'
+);
+
+$englishNouns = array(
+    'anchor', 'banana', 'beacon', 'button', 'cactus', 'comet',
+    'cookie', 'cupcake', 'disco', 'donut', 'engine', 'feather',
+    'firefly', 'gizmo', 'harbor', 'honey', 'island', 'jigsaw',
+    'kazoo', 'kernel', 'lantern', 'marble', 'meadow', 'muffin',
+    'noodle', 'orbit', 'pancake', 'pebble', 'pickle', 'pocket',
+    'puzzle', 'rainbow', 'rocket', 'sailboat', 'signal', 'spark',
+    'sprocket', 'sunbeam', 'teacup', 'ticket', 'toffee', 'tulip',
+    'velcro', 'waffle', 'widget', 'yo-yo', 'zipper', 'biscuit',
+    'castle', 'doodle', 'ember', 'fiddle', 'garden', 'hub',
+    'jacket', 'kettle', 'ladder', 'magnet', 'planet', 'ribbon'
+);
+
+$dutchAdjectives = array(
+    'aardig', 'actief', 'blij', 'blits', 'blozend', 'dapper',
+    'deftig', 'echt', 'eenvoudig', 'fijn', 'fris', 'geestig',
+    'geinig', 'gelukkig', 'gemoedelijk', 'geslepen', 'glad', 'goud',
+    'grappig', 'groots', 'helder', 'hip', 'keurig', 'klein',
+    'knap', 'koddig', 'koel', 'krachtig', 'kwiek', 'lief',
+    'luchtig', 'moedig', 'netjes', 'nieuw', 'pienter', 'pittig',
+    'prettig', 'rap', 'rustig', 'scherp', 'slim', 'snel',
+    'speels', 'sprankel', 'sterk', 'stil', 'stoer', 'stralend',
+    'tevreden', 'trots', 'vlot', 'vrolijk', 'warm', 'wijs',
+    'zacht', 'zeker', 'zinnig', 'zuiver', 'zonnig', 'zot'
+);
+
+$dutchNouns = array(
+    'appel', 'anker', 'beker', 'bel', 'berg', 'bliksem',
+    'bloem', 'boei', 'boog', 'boot', 'doos', 'druppel',
+    'duin', 'fiets', 'fluit', 'fontein', 'gieter', 'glimmer',
+    'grendel', 'haven', 'hoed', 'kaars', 'kaart', 'kasteel',
+    'ketel', 'knikker', 'koek', 'kompas', 'kraan', 'kroon',
+    'lamp', 'lint', 'magneet', 'molen', 'muis', 'munt',
+    'noot', 'pannenkoek', 'parel', 'peer', 'pijp', 'planeet',
+    'plank', 'potlood', 'raket', 'regenboog', 'ring', 'schoen',
+    'sleutel', 'slinger', 'snor', 'ster', 'taart', 'theekop',
+    'tulp', 'veer', 'vlam', 'wafel', 'zaklamp', 'zeil'
+);
+
+$englishModifiers = array(
+    'ultra', 'mega', 'mini', 'super', 'hyper', 'prime', 'fresh', 'solid'
+);
+
+$dutchModifiers = array(
+    'super', 'mega', 'mini', 'opper', 'top', 'fris', 'puur', 'mooi'
+);
+
+return array(
+    'en' => array(
+        'adjective' => expand_next_token_words($englishAdjectives, $englishModifiers, 500),
+        'noun' => expand_next_token_words($englishNouns, $englishModifiers, 500),
+    ),
+    'nl' => array(
+        'adjective' => expand_next_token_words($dutchAdjectives, $dutchModifiers, 500),
+        'noun' => expand_next_token_words($dutchNouns, $dutchModifiers, 500),
+    ),
+);
diff --git a/config/racket.zip b/config/racket.zip
new file mode 100644
index 0000000..ca936f8
Binary files /dev/null and b/config/racket.zip differ
diff --git a/gitfetcher.php b/gitfetcher.php
new file mode 100644
index 0000000..f94fde8
--- /dev/null
+++ b/gitfetcher.php
@@ -0,0 +1,578 @@
+<?php
+/*
+ * gitfetcher.php
+ *
+ * Doel:
+ *   Voor een gegeven package-naam en git repository:
+ *
+ *     1. bepaal de default branch;
+ *     2. bepaal de huidige HEAD commit SHA;
+ *     3. controleer data/<package>.json;
+ *     4. als de SHA gelijk is en data/<package>.zip bestaat: niets downloaden;
+ *     5. anders: haal de repository-zip op en sla op als data/<package>.zip.
+ *
+ * Ondersteund:
+ *   - github.com
+ *   - git.dijkewijk.nl    Gitea
+ *   - codeberg.org        Gitea
+ *
+ * GitHub:
+ *   - branch-SHA via /repos/{owner}/{repo}/branches/{branch}
+ *   - zip via /repos/{owner}/{repo}/zipball/{ref}
+ *
+ * Gitea/Codeberg:
+ *   - repository-info via /api/v1/repos/{owner}/{repo}
+ *   - branch-SHA via /api/v1/repos/{owner}/{repo}/branches/{branch}
+ *   - zip via /owner/repo/archive/{ref}.zip
+ */
+
+class GitFetcherException extends Exception
+{
+}
+
+class GitFetcher
+{
+    private $dataDir;
+    private $timeout;
+    private $connectTimeout;
+    private $userAgent;
+    private $tokensByHost;
+
+    public function __construct($options = array())
+    {
+        $this->dataDir = isset($options['data_dir'])
+            ? rtrim((string)$options['data_dir'], '/')
+            : __DIR__ . '/data';
+
+        $this->timeout = isset($options['timeout']) ? (int)$options['timeout'] : 180;
+        $this->connectTimeout = isset($options['connect_timeout']) ? (int)$options['connect_timeout'] : 20;
+        $this->userAgent = isset($options['user_agent'])
+            ? (string)$options['user_agent']
+            : 'rktsndbx-gitfetcher/1.0';
+
+        $this->tokensByHost = isset($options['tokens']) && is_array($options['tokens'])
+            ? $options['tokens']
+            : array();
+    }
+
+    /*
+     * Hoofdentry voor jouw package-route.
+     *
+     * Voorbeeld:
+     *
+     *   $gf = new GitFetcher();
+     *   $info = $gf->ensurePackageZip(
+     *       'html-parsing',
+     *       'https://github.com/soegaard/html-parsing'
+     *   );
+     *
+     * Resultaat:
+     *
+     *   data/html-parsing.zip
+     *   data/html-parsing.json
+     */
+    public function ensurePackageZip($packageName, $repoUrl)
+    {
+        $packageName = $this->safePackageName($packageName);
+        $repo = $this->parseRepositoryUrl($repoUrl);
+        $head = $this->currentHead($repo);
+
+        $zipFile = $this->packageZipFile($packageName);
+        $metaFile = $this->packageMetaFile($packageName);
+
+        $old = $this->readJsonFile($metaFile);
+
+        if (is_file($zipFile) &&
+            is_readable($zipFile) &&
+            is_array($old) &&
+            isset($old['head_sha']) &&
+            $old['head_sha'] === $head['head_sha'] &&
+            isset($old['repo_url']) &&
+            $old['repo_url'] === $repoUrl) {
+
+            return array(
+                'status'         => 'cached',
+                'package'        => $packageName,
+                'repo_url'       => $repoUrl,
+                'host'           => $repo['host'],
+                'owner'          => $repo['owner'],
+                'repo'           => $repo['repo'],
+                'default_branch' => $head['default_branch'],
+                'head_sha'       => $head['head_sha'],
+                'zip_file'       => $zipFile,
+                'meta_file'      => $metaFile,
+                'zip_bytes'      => filesize($zipFile),
+                'zip_sha256'     => hash_file('sha256', $zipFile),
+            );
+        }
+
+        $archive = $this->downloadArchiveForHead($repo, $head);
+        $this->ensureDataDir();
+
+        $tmpZip = $zipFile . '.tmp.' . getmypid();
+        $tmpMeta = $metaFile . '.tmp.' . getmypid();
+
+        if (file_put_contents($tmpZip, $archive['bytes'], LOCK_EX) === false) {
+            @unlink($tmpZip);
+            throw new GitFetcherException('Kan tijdelijke zip niet schrijven: ' . $tmpZip);
+        }
+
+        $meta = array(
+            'package'        => $packageName,
+            'repo_url'       => $repoUrl,
+            'host'           => $repo['host'],
+            'owner'          => $repo['owner'],
+            'repo'           => $repo['repo'],
+            'default_branch' => $head['default_branch'],
+            'head_sha'       => $head['head_sha'],
+            'archive_url'    => $archive['archive_url'],
+            'zip_file'       => $zipFile,
+            'zip_bytes'      => strlen($archive['bytes']),
+            'zip_sha256'     => hash('sha256', $archive['bytes']),
+            'updated_at'     => gmdate('c'),
+        );
+
+        $json = json_encode($meta, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
+
+        if ($json === false || file_put_contents($tmpMeta, $json . "\n", LOCK_EX) === false) {
+            @unlink($tmpZip);
+            @unlink($tmpMeta);
+            throw new GitFetcherException('Kan tijdelijke metadata niet schrijven: ' . $tmpMeta);
+        }
+
+        if (!rename($tmpZip, $zipFile)) {
+            @unlink($tmpZip);
+            @unlink($tmpMeta);
+            throw new GitFetcherException('Kan zip niet plaatsen: ' . $zipFile);
+        }
+
+        if (!rename($tmpMeta, $metaFile)) {
+            @unlink($tmpMeta);
+            throw new GitFetcherException('Kan metadata niet plaatsen: ' . $metaFile);
+        }
+
+        $meta['status'] = 'downloaded';
+        return $meta;
+    }
+
+    /*
+     * Alleen controleren, zonder zip te downloaden.
+     */
+    public function packageZipIsCurrent($packageName, $repoUrl)
+    {
+        $packageName = $this->safePackageName($packageName);
+        $repo = $this->parseRepositoryUrl($repoUrl);
+        $head = $this->currentHead($repo);
+
+        $zipFile = $this->packageZipFile($packageName);
+        $metaFile = $this->packageMetaFile($packageName);
+        $old = $this->readJsonFile($metaFile);
+
+        return is_file($zipFile) &&
+            is_readable($zipFile) &&
+            is_array($old) &&
+            isset($old['repo_url']) &&
+            $old['repo_url'] === $repoUrl &&
+            isset($old['head_sha']) &&
+            $old['head_sha'] === $head['head_sha'];
+    }
+
+    /*
+     * Bepaal default branch + huidige commit SHA.
+     */
+    public function currentHeadForRepositoryUrl($repoUrl)
+    {
+        $repo = $this->parseRepositoryUrl($repoUrl);
+        return $this->currentHead($repo);
+    }
+
+    private function safePackageName($packageName)
+    {
+        $packageName = (string)$packageName;
+
+        if (!preg_match('/^[A-Za-z0-9_.+-]+$/', $packageName)) {
+            throw new GitFetcherException('Ongeldige package naam: ' . $packageName);
+        }
+
+        return $packageName;
+    }
+
+    private function packageZipFile($packageName)
+    {
+        return $this->dataDir . '/' . $packageName . '.zip';
+    }
+
+    private function packageMetaFile($packageName)
+    {
+        return $this->dataDir . '/' . $packageName . '.json';
+    }
+
+    private function ensureDataDir()
+    {
+        if (!is_dir($this->dataDir)) {
+            if (!mkdir($this->dataDir, 0755, true)) {
+                throw new GitFetcherException('Kan data directory niet maken: ' . $this->dataDir);
+            }
+        }
+
+        if (!is_writable($this->dataDir)) {
+            throw new GitFetcherException('Data directory is niet schrijfbaar: ' . $this->dataDir);
+        }
+    }
+
+    private function readJsonFile($file)
+    {
+        if (!is_file($file) || !is_readable($file)) {
+            return null;
+        }
+
+        $raw = file_get_contents($file);
+
+        if ($raw === false || $raw === '') {
+            return null;
+        }
+
+        $json = json_decode($raw, true);
+
+        return is_array($json) ? $json : null;
+    }
+
+    public function parseRepositoryUrl($repoUrl)
+    {
+        $repoUrl = trim((string)$repoUrl);
+
+        /*
+         * SSH-vorm:
+         *   git@github.com:owner/repo.git
+         */
+        if (preg_match('/^git@([^:]+):(.+)$/', $repoUrl, $m)) {
+            return $this->parseHostAndPath(strtolower($m[1]), trim($m[2], '/'), $repoUrl);
+        }
+
+        if (strpos($repoUrl, 'git+https://') === 0) {
+            $repoUrl = 'https://' . substr($repoUrl, strlen('git+https://'));
+        } elseif (strpos($repoUrl, 'git+http://') === 0) {
+            $repoUrl = 'http://' . substr($repoUrl, strlen('git+http://'));
+        }
+
+        $p = parse_url($repoUrl);
+
+        if ($p === false || empty($p['host']) || empty($p['path'])) {
+            throw new GitFetcherException('Ongeldige repository URL: ' . $repoUrl);
+        }
+
+        return $this->parseHostAndPath(
+            strtolower($p['host']),
+            trim($p['path'], '/'),
+            $repoUrl
+        );
+    }
+
+    private function parseHostAndPath($host, $path, $originalUrl)
+    {
+        $kinds = array(
+            'github.com'       => 'github',
+            'git.dijkewijk.nl' => 'gitea',
+            'codeberg.org'     => 'gitea',
+        );
+
+        if (!isset($kinds[$host])) {
+            throw new GitFetcherException('Niet-ondersteunde git host: ' . $host);
+        }
+
+        if (substr($path, -4) === '.git') {
+            $path = substr($path, 0, -4);
+        }
+
+        $bits = explode('/', $path);
+
+        if (count($bits) < 2 || $bits[0] === '' || $bits[1] === '') {
+            throw new GitFetcherException('Kan owner/repo niet bepalen uit URL: ' . $originalUrl);
+        }
+
+        return array(
+            'kind'  => $kinds[$host],
+            'host'  => $host,
+            'owner' => $bits[0],
+            'repo'  => $bits[1],
+        );
+    }
+
+    private function currentHead($repo)
+    {
+        if ($repo['kind'] === 'github') {
+            return $this->githubCurrentHead($repo);
+        }
+
+        return $this->giteaCurrentHead($repo);
+    }
+
+    private function githubCurrentHead($repo)
+    {
+        $repoApi =
+            'https://api.github.com/repos/' .
+            rawurlencode($repo['owner']) . '/' .
+            rawurlencode($repo['repo']);
+
+        $repoJson = $this->httpGetJson($repoApi, $repo['host']);
+
+        if (empty($repoJson['default_branch']) || !is_string($repoJson['default_branch'])) {
+            throw new GitFetcherException('GitHub API gaf geen default_branch.');
+        }
+
+        $branch = $repoJson['default_branch'];
+
+        $branchApi =
+            'https://api.github.com/repos/' .
+            rawurlencode($repo['owner']) . '/' .
+            rawurlencode($repo['repo']) .
+            '/branches/' .
+            rawurlencode($branch);
+
+        $branchJson = $this->httpGetJson($branchApi, $repo['host']);
+
+        if (empty($branchJson['commit']['sha']) || !is_string($branchJson['commit']['sha'])) {
+            throw new GitFetcherException('GitHub API gaf geen branch commit SHA.');
+        }
+
+        return array(
+            'default_branch' => $branch,
+            'head_sha'       => $branchJson['commit']['sha'],
+        );
+    }
+
+    private function giteaCurrentHead($repo)
+    {
+        $repoApi =
+            'https://' . $repo['host'] .
+            '/api/v1/repos/' .
+            rawurlencode($repo['owner']) . '/' .
+            rawurlencode($repo['repo']);
+
+        $repoJson = $this->httpGetJson($repoApi, $repo['host']);
+
+        $branch = null;
+
+        if (!empty($repoJson['default_branch']) && is_string($repoJson['default_branch'])) {
+            $branch = $repoJson['default_branch'];
+        } elseif (!empty($repoJson['default_branch_name']) && is_string($repoJson['default_branch_name'])) {
+            $branch = $repoJson['default_branch_name'];
+        }
+
+        if ($branch === null || $branch === '') {
+            $branch = 'main';
+        }
+
+        $branchApi =
+            'https://' . $repo['host'] .
+            '/api/v1/repos/' .
+            rawurlencode($repo['owner']) . '/' .
+            rawurlencode($repo['repo']) .
+            '/branches/' .
+            rawurlencode($branch);
+
+        $branchJson = $this->httpGetJson($branchApi, $repo['host']);
+        $sha = $this->extractGiteaBranchSha($branchJson);
+
+        if ($sha === null || $sha === '') {
+            throw new GitFetcherException('Gitea API gaf geen branch commit SHA.');
+        }
+
+        return array(
+            'default_branch' => $branch,
+            'head_sha'       => $sha,
+        );
+    }
+
+    private function extractGiteaBranchSha($branchJson)
+    {
+        /*
+         * Gitea/Forgejo varianten komen in de praktijk voor als:
+         *   commit.id
+         *   commit.sha
+         *   commit.commit.id
+         */
+        $paths = array(
+            array('commit', 'id'),
+            array('commit', 'sha'),
+            array('commit', 'commit', 'id'),
+        );
+
+        foreach ($paths as $path) {
+            $v = $branchJson;
+
+            foreach ($path as $k) {
+                if (!is_array($v) || !array_key_exists($k, $v)) {
+                    $v = null;
+                    break;
+                }
+
+                $v = $v[$k];
+            }
+
+            if (is_string($v) && preg_match('/^[0-9a-f]{7,40}$/i', $v)) {
+                return $v;
+            }
+        }
+
+        return null;
+    }
+
+    private function downloadArchiveForHead($repo, $head)
+    {
+        /*
+         * Bij voorkeur downloaden we op exacte SHA, niet op branchnaam.
+         * Dan hoort de zip exact bij de SHA die we in metadata opslaan.
+         */
+        $shaUrl = $this->archiveUrl($repo, $head['head_sha']);
+        $branchUrl = $this->archiveUrl($repo, $head['default_branch']);
+
+        try {
+            $bytes = $this->httpGet($shaUrl, $repo['host'], true);
+            return array(
+                'archive_url' => $shaUrl,
+                'bytes'       => $bytes,
+            );
+        } catch (GitFetcherException $e) {
+            /*
+             * Sommige Gitea/Forgejo instanties accepteren branch/tag ref wel
+             * maar commit-SHA niet in archive/<ref>.zip. Dan fallback naar
+             * branch. De SHA-check blijft alsnog gebaseerd op de API.
+             */
+            $bytes = $this->httpGet($branchUrl, $repo['host'], true);
+            return array(
+                'archive_url' => $branchUrl,
+                'bytes'       => $bytes,
+            );
+        }
+    }
+
+    private function archiveUrl($repo, $ref)
+    {
+        if ($ref === '') {
+            throw new GitFetcherException('Lege archive ref.');
+        }
+
+        if ($repo['kind'] === 'github') {
+            return
+                'https://api.github.com/repos/' .
+                rawurlencode($repo['owner']) . '/' .
+                rawurlencode($repo['repo']) .
+                '/zipball/' .
+                rawurlencode($ref);
+        }
+
+        return
+            'https://' . $repo['host'] . '/' .
+            rawurlencode($repo['owner']) . '/' .
+            rawurlencode($repo['repo']) .
+            '/archive/' .
+            rawurlencode($ref) .
+            '.zip';
+    }
+
+    private function httpGetJson($url, $host)
+    {
+        $body = $this->httpGet($url, $host, true);
+        $json = json_decode($body, true);
+
+        if (!is_array($json)) {
+            throw new GitFetcherException('Response is geen JSON: ' . $url);
+        }
+
+        return $json;
+    }
+
+    private function httpGet($url, $host, $followRedirects)
+    {
+        if (!function_exists('curl_init')) {
+            return $this->httpGetWithoutCurl($url, $host);
+        }
+
+        $headers = array(
+            'User-Agent: ' . $this->userAgent,
+        );
+
+        if ($host === 'github.com') {
+            $headers[] = 'Accept: application/vnd.github+json';
+            $headers[] = 'X-GitHub-Api-Version: 2022-11-28';
+        }
+
+        if (!empty($this->tokensByHost[$host])) {
+            if ($host === 'github.com') {
+                $headers[] = 'Authorization: Bearer ' . $this->tokensByHost[$host];
+            } else {
+                $headers[] = 'Authorization: token ' . $this->tokensByHost[$host];
+            }
+        }
+
+        $ch = curl_init($url);
+
+        curl_setopt_array($ch, array(
+            CURLOPT_RETURNTRANSFER => true,
+            CURLOPT_FOLLOWLOCATION => $followRedirects ? true : false,
+            CURLOPT_CONNECTTIMEOUT => $this->connectTimeout,
+            CURLOPT_TIMEOUT        => $this->timeout,
+            CURLOPT_USERAGENT      => $this->userAgent,
+            CURLOPT_HTTPHEADER     => $headers,
+            CURLOPT_FAILONERROR    => false,
+        ));
+
+        $body = curl_exec($ch);
+
+        if ($body === false) {
+            $err = curl_error($ch);
+            curl_close($ch);
+            throw new GitFetcherException('HTTP request mislukt: ' . $err . ' url=' . $url);
+        }
+
+        $status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+        curl_close($ch);
+
+        if ($status < 200 || $status >= 300) {
+            throw new GitFetcherException(
+                'HTTP status ' . $status . ' voor ' . $url . "\n" .
+                substr((string)$body, 0, 500)
+            );
+        }
+
+        return $body;
+    }
+
+    private function httpGetWithoutCurl($url, $host)
+    {
+        $headers = array(
+            'User-Agent: ' . $this->userAgent,
+        );
+
+        if ($host === 'github.com') {
+            $headers[] = 'Accept: application/vnd.github+json';
+            $headers[] = 'X-GitHub-Api-Version: 2022-11-28';
+        }
+
+        if (!empty($this->tokensByHost[$host])) {
+            if ($host === 'github.com') {
+                $headers[] = 'Authorization: Bearer ' . $this->tokensByHost[$host];
+            } else {
+                $headers[] = 'Authorization: token ' . $this->tokensByHost[$host];
+            }
+        }
+
+        $ctx = stream_context_create(array(
+            'http' => array(
+                'method'        => 'GET',
+                'timeout'       => $this->timeout,
+                'ignore_errors' => true,
+                'header'        => implode("\r\n", $headers) . "\r\n",
+            ),
+        ));
+
+        $body = @file_get_contents($url, false, $ctx);
+
+        if ($body === false) {
+            throw new GitFetcherException('HTTP request mislukt: ' . $url);
+        }
+
+        return $body;
+    }
+}
\ No newline at end of file
diff --git a/header.php b/header.php
new file mode 100644
index 0000000..6fa928b
--- /dev/null
+++ b/header.php
@@ -0,0 +1,94 @@
+<?php
+/*
+ * header.php
+ *
+ * Shared page header renderer for logged-in application pages.
+ */
+
+function app_header_h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function render_app_header($options)
+{
+    $title = (string)($options['title'] ?? '');
+    $navItems = $options['nav_items'] ?? array();
+    $user = $options['user'] ?? null;
+    $userPrefix = (string)($options['user_prefix'] ?? '');
+    $adminLabel = (string)($options['admin_label'] ?? 'admin');
+    $languageLabel = (string)($options['language_label'] ?? 'Language');
+    $language = (string)($options['language'] ?? 'en');
+    $languages = $options['languages'] ?? array();
+    $languageAction = (string)($options['language_action'] ?? '/');
+    $languageHidden = $options['language_hidden'] ?? array();
+    $logoutAction = (string)($options['logout_action'] ?? '');
+    $logoutLabel = (string)($options['logout_label'] ?? '');
+    $message = (string)($options['message'] ?? '');
+    $error = (string)($options['error'] ?? '');
+    ?>
+<header class="page-header">
+<div class="page-titlebar">
+<h1><?= app_header_h($title) ?></h1>
+
+<nav class="header-nav" aria-label="<?= app_header_h($title) ?> navigation">
+<?php foreach ($navItems as $item): ?>
+<?php if (!empty($item['separator_before'])): ?>
+<span class="nav-separator" aria-hidden="true">|</span>
+<?php endif; ?>
+<?php if (!empty($item['active'])): ?>
+<strong><?= app_header_h($item['label'] ?? '') ?></strong>
+<?php else: ?>
+<a href="<?= app_header_h($item['url'] ?? '#') ?>"><?= app_header_h($item['label'] ?? '') ?></a>
+<?php endif; ?>
+<?php endforeach; ?>
+
+<?php if ($logoutAction !== '' && $logoutLabel !== ''): ?>
+<span class="nav-separator" aria-hidden="true">|</span>
+<form class="header-action-form" method="post" action="<?= app_header_h($logoutAction) ?>">
+<input type="hidden" name="action" value="logout">
+<button type="submit"><?= app_header_h($logoutLabel) ?></button>
+</form>
+<?php endif; ?>
+
+<?php if ($user !== null): ?>
+<span class="nav-separator" aria-hidden="true">|</span>
+<span class="nav-user">
+<?php if ($userPrefix !== ''): ?>
+<?= app_header_h($userPrefix) ?>
+<?php endif; ?>
+<?= app_header_h($user->displayName()) ?>
+<?php if ($user->isAdmin()): ?>
+<span class="small">(<?= app_header_h($adminLabel) ?>)</span>
+<?php endif; ?>
+</span>
+<?php endif; ?>
+
+<form class="header-language-form" method="get" action="<?= app_header_h($languageAction) ?>">
+<?php foreach ($languageHidden as $name => $value): ?>
+<input type="hidden" name="<?= app_header_h($name) ?>" value="<?= app_header_h($value) ?>">
+<?php endforeach; ?>
+<label>
+<?= app_header_h($languageLabel) ?>
+<select name="lang" onchange="this.form.submit()">
+<?php foreach ($languages as $lang => $label): ?>
+<option value="<?= app_header_h($lang) ?>" <?= $lang === $language ? 'selected' : '' ?>>
+<?= app_header_h($label) ?>
+</option>
+<?php endforeach; ?>
+</select>
+</label>
+</form>
+</nav>
+</div>
+
+<?php if ($message !== ''): ?>
+<div class="message"><?= app_header_h($message) ?></div>
+<?php endif; ?>
+
+<?php if ($error !== ''): ?>
+<div class="error"><?= app_header_h($error) ?></div>
+<?php endif; ?>
+</header>
+    <?php
+}
diff --git a/index.php b/index.php
new file mode 100644
index 0000000..fa04ecf
--- /dev/null
+++ b/index.php
@@ -0,0 +1,470 @@
+<?php
+/*
+ * index.php
+ *
+ * Menselijk startpunt voor Racket sandbox.
+ *
+ * Niet ingelogd:
+ *   - verwijst naar login
+ *
+ * Ingelogd:
+ *   - bootstrap-link genereren
+ *   - logout
+ *
+ * Admin:
+ *   - gebruikersoverzicht
+ *   - admin/enabled vlaggen wijzigen
+ *   - wachtwoord wijzigen
+ *   - gebruiker verwijderen
+ */
+
+require_once __DIR__ . '/auth.php';
+require_once __DIR__ . '/header.php';
+require_once __DIR__ . '/languagestore.php';
+require_once __DIR__ . '/nexttoken.php';
+require_once __DIR__ . '/promptstore.php';
+require_once __DIR__ . '/usersettings.php';
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+$DB_FILE = __DIR__ . '/data/racket-sandbox.sqlite';
+
+$auth = new RacketSandboxAuth($DB_FILE);
+$languageStore = new LanguageStore($DB_FILE);
+$tokens = new NextTokenStore($DB_FILE);
+$promptStore = new PromptStore($DB_FILE);
+$userSettings = new UserSettingsStore($DB_FILE);
+
+$message = '';
+$error = '';
+$issuedLink = '';
+$bootstrapPrompts = array();
+
+define('BOOTSTRAP_TTL_DEFAULT_MINUTES', 120);
+define('BOOTSTRAP_TTL_MIN_MINUTES', 30);
+define('BOOTSTRAP_TTL_MAX_MINUTES', 8 * 60);
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function get_value($name, $default = '')
+{
+    return $_GET[$name] ?? $default;
+}
+
+function t($key, $fallback = null)
+{
+    global $languageStore, $language;
+
+    return $languageStore->translate($key, $language, $fallback);
+}
+
+function current_scheme()
+{
+    if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
+        return strtolower(trim(explode(',', $_SERVER['HTTP_X_FORWARDED_PROTO'])[0]));
+    }
+
+    return (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https' : 'http';
+}
+
+function current_host()
+{
+    return $_SERVER['HTTP_HOST'] ?? 'localhost';
+}
+
+function bootstrap_link_for_token($token)
+{
+    return current_scheme() . '://' . current_host() .
+        '/bootstrap-racket?next=' . rawurlencode($token);
+}
+
+function post_value($name, $default = '')
+{
+    return $_POST[$name] ?? $default;
+}
+
+function post_bool($name)
+{
+    return isset($_POST[$name]) && $_POST[$name] === '1';
+}
+
+function create_next_token($tokens, $ttlSeconds, $meta)
+{
+    /*
+     * Ondersteunt zowel:
+     *   create($ttl)
+     * als:
+     *   create($ttl, $meta)
+     */
+    $rm = new ReflectionMethod($tokens, 'create');
+
+    if ($rm->getNumberOfParameters() >= 2) {
+        return $tokens->create($ttlSeconds, $meta);
+    }
+
+    return $tokens->create($ttlSeconds);
+}
+
+function clamp_bootstrap_ttl_minutes($ttlMinutes)
+{
+    $ttlMinutes = (int)$ttlMinutes;
+
+    if ($ttlMinutes < BOOTSTRAP_TTL_MIN_MINUTES) {
+        return BOOTSTRAP_TTL_MIN_MINUTES;
+    }
+
+    if ($ttlMinutes > BOOTSTRAP_TTL_MAX_MINUTES) {
+        return BOOTSTRAP_TTL_MAX_MINUTES;
+    }
+
+    return $ttlMinutes;
+}
+
+function resolve_user_language($userSettings, $userId, $allowedLanguages)
+{
+    $language = isset($_GET['lang'])
+        ? (string)$_GET['lang']
+        : (string)$userSettings->get($userId, 'language', 'en');
+
+    if (!in_array($language, $allowedLanguages, true)) {
+        $language = 'en';
+    }
+
+    $userSettings->set($userId, 'language', $language);
+
+    return $language;
+}
+
+$currentUser = $auth->currentUser();
+
+if ($currentUser === null) {
+    header('Location: /login.php');
+    exit;
+}
+
+$language = resolve_user_language(
+    $userSettings,
+    $currentUser->id(),
+    $languageStore->supportedLanguages()
+);
+
+$languageStore->seedDefaults(array(
+    'app.title' => array('en' => 'Racket sandbox', 'nl' => 'Racket sandbox'),
+    'app.manage_prompts' => array('en' => 'Manage prompts', 'nl' => 'Prompts beheren'),
+    'app.logout' => array('en' => 'Logout', 'nl' => 'Uitloggen'),
+    'app.language' => array('en' => 'Language', 'nl' => 'Taal'),
+    'app.logged_in_as' => array('en' => 'Logged in as:', 'nl' => 'Ingelogd als:'),
+    'app.admin' => array('en' => 'admin', 'nl' => 'admin'),
+    'app.bootstrap_link' => array('en' => 'Bootstrap link', 'nl' => 'Bootstraplink'),
+    'app.generate_bootstrap_link' => array('en' => 'Generate bootstrap link', 'nl' => 'Bootstraplink genereren'),
+    'app.ttl_minutes' => array('en' => 'TTL in minutes', 'nl' => 'TTL in minuten'),
+    'app.ttl_range_help' => array('en' => 'Allowed range: 30 minutes to 8 hours.', 'nl' => 'Toegestaan bereik: 30 minuten tot 8 uur.'),
+    'app.generated_link' => array('en' => 'Generated link', 'nl' => 'Gegenereerde link'),
+    'app.copy' => array('en' => 'Copy', 'nl' => 'Kopieer'),
+    'app.copied' => array('en' => 'Copied', 'nl' => 'Gekopieerd'),
+    'app.generated_link_help' => array(
+        'en' => 'Give this link to the AI agent. The agent should start from this link and then only follow links from the generated HTML pages.',
+        'nl' => 'Geef deze link aan de AI-agent. De agent moet vanaf deze link starten en daarna alleen links volgen vanuit de gegenereerde HTML-paginas.'
+    ),
+    'app.select_prompt' => array('en' => 'Select prompt', 'nl' => 'Prompt selecteren'),
+    'app.copy_full_prompt' => array('en' => 'Copy full prompt', 'nl' => 'Volledige prompt kopieren'),
+    'app.bootstrap_prompt_help' => array(
+        'en' => 'Choose one of your prompts. The placeholder {{bootstrap-racket-link}} is replaced by the generated bootstrap link.',
+        'nl' => 'Kies een van je prompts. De placeholder {{bootstrap-racket-link}} wordt vervangen door de gegenereerde bootstraplink.'
+    ),
+    'app.no_bootstrap_prompts' => array(
+        'en' => 'No personal prompts are available for this language. Copy a default prompt first from prompt management.',
+        'nl' => 'Er zijn geen persoonlijke prompts beschikbaar voor deze taal. Kopieer eerst een standaardprompt vanuit promptbeheer.'
+    ),
+    'app.user_management' => array('en' => 'User management', 'nl' => 'Gebruikersbeheer'),
+    'app.configuration' => array('en' => 'Configuration', 'nl' => 'Configuratie'),
+    'app.user_management_help' => array(
+        'en' => 'Users are registered manually by email address, full name and password. This page only manages existing users.',
+        'nl' => 'Gebruikers worden handmatig geregistreerd met e-mailadres, volledige naam en wachtwoord. Deze pagina beheert alleen bestaande gebruikers.'
+    ),
+    'app.id' => array('en' => 'ID', 'nl' => 'ID'),
+    'app.full_name' => array('en' => 'Full name', 'nl' => 'Volledige naam'),
+    'app.email' => array('en' => 'Email', 'nl' => 'E-mail'),
+    'app.enabled' => array('en' => 'Enabled', 'nl' => 'Ingeschakeld'),
+    'app.created' => array('en' => 'Created', 'nl' => 'Gemaakt'),
+    'app.last_login' => array('en' => 'Last login', 'nl' => 'Laatste login'),
+    'app.actions' => array('en' => 'Actions', 'nl' => 'Acties'),
+    'app.yes' => array('en' => 'yes', 'nl' => 'ja'),
+    'app.no' => array('en' => 'no', 'nl' => 'nee'),
+    'app.save_flags' => array('en' => 'Save flags', 'nl' => 'Vlaggen opslaan'),
+    'app.new_password' => array('en' => 'New password', 'nl' => 'Nieuw wachtwoord'),
+    'app.change_password' => array('en' => 'Change password', 'nl' => 'Wachtwoord wijzigen'),
+    'app.delete_user' => array('en' => 'Delete user', 'nl' => 'Gebruiker verwijderen'),
+    'app.delete_user_confirm' => array('en' => 'Delete user', 'nl' => 'Gebruiker verwijderen'),
+    'app.cannot_delete_self' => array('en' => 'You cannot delete your own account.', 'nl' => 'Je kunt je eigen account niet verwijderen.'),
+    'app.bootstrap_link_issued' => array('en' => 'Bootstrap link issued.', 'nl' => 'Bootstraplink aangemaakt.'),
+    'app.password_changed_for' => array('en' => 'Password changed for:', 'nl' => 'Wachtwoord gewijzigd voor:'),
+    'app.user_flags_updated' => array('en' => 'User flags updated.', 'nl' => 'Gebruikersvlaggen bijgewerkt.'),
+    'app.user_deleted' => array('en' => 'User deleted.', 'nl' => 'Gebruiker verwijderd.'),
+    'app.admin_rights_required' => array('en' => 'Admin rights required.', 'nl' => 'Adminrechten vereist.'),
+    'app.cannot_remove_own_admin' => array('en' => 'You cannot remove your own admin rights.', 'nl' => 'Je kunt je eigen adminrechten niet verwijderen.'),
+    'app.cannot_disable_self' => array('en' => 'You cannot disable your own account.', 'nl' => 'Je kunt je eigen account niet uitschakelen.'),
+    'app.unknown_action' => array('en' => 'Unknown action:', 'nl' => 'Onbekende actie:'),
+));
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    $action = post_value('action');
+
+    try {
+        if ($action === 'logout') {
+            $auth->logout();
+            header('Location: /login.php');
+            exit;
+        }
+
+        $currentUser = $auth->currentUser();
+
+        if ($currentUser === null) {
+            header('Location: /login.php');
+            exit;
+        }
+
+        if ($action === 'issue_bootstrap') {
+            $ttlMinutes = clamp_bootstrap_ttl_minutes(
+                post_value('ttl_minutes', (string)BOOTSTRAP_TTL_DEFAULT_MINUTES)
+            );
+
+            $userSettings->set($currentUser->id(), 'bootstrap_ttl_minutes', (string)$ttlMinutes);
+
+            $token = create_next_token(
+                $tokens,
+                $ttlMinutes * 60,
+                array(
+                    'user_id' => $currentUser->id(),
+                    'email' => $currentUser->email(),
+                    'full_name' => $currentUser->fullName(),
+                    'purpose' => 'racket-bootstrap',
+                )
+            );
+
+            $issuedLink = bootstrap_link_for_token($token);
+            $message = t('app.bootstrap_link_issued', 'Bootstrap link issued.');
+        } else {
+            if (!$currentUser->isAdmin()) {
+                throw new Exception(t('app.admin_rights_required', 'Admin rights required.'));
+            }
+
+            if ($action === 'set_password') {
+                $email = trim(post_value('email'));
+                $password = (string)post_value('password');
+
+                $auth->setPassword($email, $password);
+                $message = t('app.password_changed_for', 'Password changed for:') . ' ' . $email;
+            } elseif ($action === 'set_flags') {
+                $userId = (int)post_value('user_id');
+                $isAdmin = post_bool('is_admin');
+                $isEnabled = post_bool('is_enabled');
+
+                if ($userId === $currentUser->id() && !$isAdmin) {
+                    throw new Exception(t('app.cannot_remove_own_admin', 'You cannot remove your own admin rights.'));
+                }
+
+                if ($userId === $currentUser->id() && !$isEnabled) {
+                    throw new Exception(t('app.cannot_disable_self', 'You cannot disable your own account.'));
+                }
+
+                $auth->setAdmin($userId, $isAdmin);
+                $auth->setEnabled($userId, $isEnabled);
+                $message = t('app.user_flags_updated', 'User flags updated.');
+            } elseif ($action === 'delete_user') {
+                $userId = (int)post_value('user_id');
+
+                if ($userId === $currentUser->id()) {
+                    throw new Exception('You cannot delete your own account.');
+                }
+
+                $auth->deleteUser($userId);
+                $message = t('app.user_deleted', 'User deleted.');
+            } elseif ($action !== '') {
+                throw new Exception(t('app.unknown_action', 'Unknown action:') . ' ' . $action);
+            }
+        }
+    } catch (Throwable $e) {
+        $error = $e->getMessage();
+    }
+}
+
+$currentUser = $auth->currentUser();
+
+if ($currentUser === null) {
+    header('Location: /login.php');
+    exit;
+}
+
+$bootstrapTtlMinutes = clamp_bootstrap_ttl_minutes(
+    $userSettings->get(
+        $currentUser->id(),
+        'bootstrap_ttl_minutes',
+        (string)BOOTSTRAP_TTL_DEFAULT_MINUTES
+    )
+);
+
+foreach ($promptStore->listPrompts($currentUser->id(), $language) as $prompt) {
+    $bootstrapPrompts[] = array(
+        'id' => $prompt->id(),
+        'name' => $prompt->name(),
+        'content' => $prompt->content(),
+    );
+}
+
+$headerLanguages = array();
+
+foreach ($languageStore->supportedLanguages() as $lang) {
+    $headerLanguages[$lang] = $languageStore->languageLabel($lang);
+}
+
+$headerNavItems = array(
+    array(
+        'label' => t('app.manage_prompts', 'Manage prompts'),
+        'url' => '/prompts?lang=' . rawurlencode($language),
+    ),
+);
+
+if ($currentUser->isAdmin()) {
+    $headerNavItems[] = array(
+        'label' => t('app.user_management', 'User management'),
+        'url' => '/users?lang=' . rawurlencode($language),
+        'separator_before' => true,
+    );
+    $headerNavItems[] = array(
+        'label' => t('app.configuration', 'Configuration'),
+        'url' => '/admin-config?lang=' . rawurlencode($language),
+        'separator_before' => true,
+    );
+}
+
+header('Content-Type: text/html; charset=utf-8');
+?>
+<!doctype html>
+<html lang="<?= h($language) ?>">
+<head>
+<meta charset="utf-8">
+<title><?= h(t('app.title', 'Racket sandbox')) ?></title>
+<link rel="stylesheet" href="/styles.css">
+</head>
+<body>
+
+<div class="page">
+
+<?php
+render_app_header(array(
+    'title' => t('app.title', 'Racket sandbox'),
+    'nav_items' => $headerNavItems,
+    'user' => $currentUser,
+    'user_prefix' => t('app.logged_in_as', 'Logged in as:'),
+    'admin_label' => t('app.admin', 'admin'),
+    'language_label' => t('app.language', 'Language'),
+    'language' => $language,
+    'languages' => $headerLanguages,
+    'language_action' => '/',
+    'logout_action' => '/?lang=' . rawurlencode($language),
+    'logout_label' => t('app.logout', 'Logout'),
+    'message' => $message,
+    'error' => $error,
+));
+?>
+
+<main class="page-main dashboard-main">
+
+<section class="panel">
+<h2><?= h(t('app.bootstrap_link', 'Bootstrap link')) ?></h2>
+
+<fieldset>
+<legend><?= h(t('app.generate_bootstrap_link', 'Generate bootstrap link')) ?></legend>
+
+<div class="bootstrap-result-grid <?= $issuedLink !== '' ? 'has-prompt' : '' ?>">
+<div>
+<form method="post" action="/?lang=<?= h($language) ?>">
+<input type="hidden" name="action" value="issue_bootstrap">
+
+<label>
+<?= h(t('app.ttl_minutes', 'TTL in minutes')) ?><br>
+<input type="number"
+       name="ttl_minutes"
+       value="<?= h($bootstrapTtlMinutes) ?>"
+       min="<?= h(BOOTSTRAP_TTL_MIN_MINUTES) ?>"
+       max="<?= h(BOOTSTRAP_TTL_MAX_MINUTES) ?>">
+</label>
+<p class="small"><?= h(t('app.ttl_range_help', 'Allowed range: 30 minutes to 8 hours.')) ?></p>
+
+<button type="submit"><?= h(t('app.generate_bootstrap_link', 'Generate bootstrap link')) ?></button>
+</form>
+
+<?php if ($issuedLink !== ''): ?>
+<h3><?= h(t('app.generated_link', 'Generated link')) ?></h3>
+<div class="generated-link-row">
+<a href="<?= h($issuedLink) ?>" target="_blank" rel="noopener noreferrer"><?= h($issuedLink) ?></a>
+<button type="button"
+        class="js-copy-button"
+        data-copy-text="<?= h($issuedLink) ?>"
+        data-copy-label="<?= h(t('app.copy', 'Copy')) ?>"
+        data-copied-label="<?= h(t('app.copied', 'Copied')) ?>">
+<?= h(t('app.copy', 'Copy')) ?>
+</button>
+</div>
+<?php endif; ?>
+</div>
+
+<?php if ($issuedLink !== ''): ?>
+<div>
+<h3><?= h(t('app.copy_full_prompt', 'Copy full prompt')) ?></h3>
+<p>
+<?= h(t('app.bootstrap_prompt_help', 'Choose one of your prompts. The placeholder {{bootstrap-racket-link}} is replaced by the generated bootstrap link.')) ?>
+</p>
+
+<?php if (count($bootstrapPrompts) > 0): ?>
+<div class="bootstrap-prompt-tool">
+<label>
+<?= h(t('app.select_prompt', 'Select prompt')) ?><br>
+<select id="bootstrapPromptSelect">
+<?php foreach ($bootstrapPrompts as $prompt): ?>
+<option value="<?= h($prompt['id']) ?>"><?= h($prompt['name']) ?></option>
+<?php endforeach; ?>
+</select>
+</label>
+
+<textarea id="bootstrapPromptOutput" readonly rows="12"></textarea>
+
+<button type="button"
+        class="js-copy-button"
+        data-copy-target="bootstrapPromptOutput"
+        data-copy-label="<?= h(t('app.copy', 'Copy')) ?>"
+        data-copied-label="<?= h(t('app.copied', 'Copied')) ?>">
+<?= h(t('app.copy_full_prompt', 'Copy full prompt')) ?>
+</button>
+</div>
+<script type="application/json" id="bootstrapPromptData">
+<?= json_encode(array(
+    'link' => $issuedLink,
+    'prompts' => $bootstrapPrompts,
+), JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT) ?>
+</script>
+<?php else: ?>
+<p class="small"><?= h(t('app.no_bootstrap_prompts', 'No personal prompts are available for this language. Copy a default prompt first from prompt management.')) ?></p>
+<?php endif; ?>
+</div>
+<?php endif; ?>
+</div>
+
+</fieldset>
+</section>
+
+</main>
+
+</div>
+
+<script src="/clipboard.js" defer></script>
+<script src="/bootstrap-prompt.js" defer></script>
+</body>
+</html>
diff --git a/languagestore.php b/languagestore.php
new file mode 100644
index 0000000..26e8dbe
--- /dev/null
+++ b/languagestore.php
@@ -0,0 +1,205 @@
+<?php
+/*
+ * languagestore.php
+ *
+ * Small SQLite-backed translation module.
+ *
+ * Database:
+ *   data/racket-sandbox.sqlite
+ */
+
+class LanguageStoreException extends Exception
+{
+}
+
+class LanguageStore
+{
+    private $db;
+    private $fallbackLanguage;
+
+    public function __construct($dbFile, $fallbackLanguage = 'en')
+    {
+        $dir = dirname($dbFile);
+
+        if (!is_dir($dir)) {
+            if (!mkdir($dir, 0700, true)) {
+                throw new LanguageStoreException('Could not create database directory: ' . $dir);
+            }
+        }
+
+        $this->fallbackLanguage = $this->safeLanguage($fallbackLanguage);
+
+        $this->db = new PDO('sqlite:' . $dbFile);
+        $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+        $this->db->exec('PRAGMA journal_mode = WAL');
+        $this->db->exec('PRAGMA busy_timeout = 5000');
+
+        $this->init();
+    }
+
+    private function init()
+    {
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS app_translations (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                translation_key TEXT NOT NULL,
+                language TEXT NOT NULL,
+                text TEXT NOT NULL,
+                created_at INTEGER NOT NULL,
+                updated_at INTEGER NOT NULL,
+                UNIQUE(translation_key, language)
+            )'
+        );
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_app_translations_language
+             ON app_translations(language, translation_key)'
+        );
+    }
+
+    public function translate($key, $language, $fallback = null)
+    {
+        $key = $this->safeKey($key);
+        $language = $this->safeLanguage($language);
+
+        $text = $this->findText($key, $language);
+
+        if ($text !== null) {
+            return $text;
+        }
+
+        if ($language !== $this->fallbackLanguage) {
+            $text = $this->findText($key, $this->fallbackLanguage);
+
+            if ($text !== null) {
+                return $text;
+            }
+        }
+
+        return $fallback !== null ? (string)$fallback : $key;
+    }
+
+    public function setTranslation($key, $language, $text)
+    {
+        $key = $this->safeKey($key);
+        $language = $this->safeLanguage($language);
+        $text = (string)$text;
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO app_translations
+             (translation_key, language, text, created_at, updated_at)
+             VALUES
+             (:translation_key, :language, :text, :created_at, :updated_at)
+             ON CONFLICT(translation_key, language)
+             DO UPDATE SET text = excluded.text, updated_at = excluded.updated_at'
+        );
+
+        $stmt->execute(array(
+            ':translation_key' => $key,
+            ':language' => $language,
+            ':text' => $text,
+            ':created_at' => $now,
+            ':updated_at' => $now,
+        ));
+    }
+
+    public function seedDefaults($translations)
+    {
+        foreach ($translations as $key => $byLanguage) {
+            foreach ($byLanguage as $language => $text) {
+                if (!$this->hasTranslation($key, $language)) {
+                    $this->setTranslation($key, $language, $text);
+                }
+            }
+        }
+    }
+
+    public function listTranslations($language = null)
+    {
+        if ($language !== null && $language !== '') {
+            $stmt = $this->db->prepare(
+                'SELECT translation_key, language, text, created_at, updated_at
+                 FROM app_translations
+                 WHERE language = :language
+                 ORDER BY translation_key'
+            );
+            $stmt->execute(array(':language' => $this->safeLanguage($language)));
+        } else {
+            $stmt = $this->db->query(
+                'SELECT translation_key, language, text, created_at, updated_at
+                 FROM app_translations
+                 ORDER BY translation_key, language'
+            );
+        }
+
+        return $stmt->fetchAll(PDO::FETCH_ASSOC);
+    }
+
+    public function supportedLanguages()
+    {
+        return array('en', 'nl');
+    }
+
+    public function languageLabel($language)
+    {
+        if ($language === 'nl') {
+            return 'Nederlands';
+        }
+
+        if ($language === 'en') {
+            return 'English';
+        }
+
+        return $language;
+    }
+
+    private function findText($key, $language)
+    {
+        $stmt = $this->db->prepare(
+            'SELECT text
+             FROM app_translations
+             WHERE translation_key = :translation_key
+               AND language = :language'
+        );
+        $stmt->execute(array(
+            ':translation_key' => $key,
+            ':language' => $language,
+        ));
+
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        return $row ? (string)$row['text'] : null;
+    }
+
+    private function hasTranslation($key, $language)
+    {
+        return $this->findText($this->safeKey($key), $this->safeLanguage($language)) !== null;
+    }
+
+    private function safeKey($key)
+    {
+        $key = trim((string)$key);
+
+        if ($key === '') {
+            throw new LanguageStoreException('Translation key is required.');
+        }
+
+        if (strlen($key) > 160) {
+            throw new LanguageStoreException('Translation key is too long.');
+        }
+
+        return $key;
+    }
+
+    private function safeLanguage($language)
+    {
+        $language = strtolower(trim((string)$language));
+
+        if (!preg_match('/^[a-z][a-z0-9_-]{1,15}$/', $language)) {
+            throw new LanguageStoreException('Invalid language code.');
+        }
+
+        return $language;
+    }
+}
diff --git a/lib/catalog-http.php b/lib/catalog-http.php
new file mode 100644
index 0000000..6372d5e
--- /dev/null
+++ b/lib/catalog-http.php
@@ -0,0 +1,228 @@
+<?php
+
+function catalog_http_normalize_header_name($name)
+{
+    return strtolower(trim($name));
+}
+
+function catalog_http_ensure_dir($dir)
+{
+    if (!is_dir($dir)) {
+        if (!mkdir($dir, 0755, true)) {
+            throw new RuntimeException('Kan cache directory niet maken: ' . $dir);
+        }
+    }
+
+    if (!is_writable($dir)) {
+        throw new RuntimeException('Cache directory is niet schrijfbaar: ' . $dir);
+    }
+}
+
+function catalog_http_read_meta($metaFile)
+{
+    if ($metaFile === null || !is_file($metaFile)) {
+        return array();
+    }
+
+    $json = file_get_contents($metaFile);
+
+    if ($json === false || $json === '') {
+        return array();
+    }
+
+    $meta = json_decode($json, true);
+
+    return is_array($meta) ? $meta : array();
+}
+
+function catalog_http_write_meta($metaFile, $meta)
+{
+    if ($metaFile === null) {
+        return;
+    }
+
+    $json = json_encode($meta, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
+
+    if ($json === false) {
+        throw new RuntimeException('Kan catalogus-cache metadata niet coderen.');
+    }
+
+    if (file_put_contents($metaFile, $json . "\n", LOCK_EX) === false) {
+        throw new RuntimeException('Kan catalogus-cache metadata niet schrijven: ' . $metaFile);
+    }
+}
+
+function catalog_http_validator_headers($meta)
+{
+    $headers = array();
+
+    if (!empty($meta['etag'])) {
+        $headers[] = 'If-None-Match: ' . $meta['etag'];
+    }
+
+    if (!empty($meta['last_modified'])) {
+        $headers[] = 'If-Modified-Since: ' . $meta['last_modified'];
+    }
+
+    return $headers;
+}
+
+function catalog_http_fetch($url, $requestHeaders = array(), $userAgent = 'rktsndbx-catalog/1.0', $timeout = 180)
+{
+    if (function_exists('curl_init')) {
+        $ch = curl_init($url);
+        $responseHeaders = array();
+
+        curl_setopt_array($ch, array(
+            CURLOPT_RETURNTRANSFER => true,
+            CURLOPT_FOLLOWLOCATION => true,
+            CURLOPT_CONNECTTIMEOUT => 20,
+            CURLOPT_TIMEOUT        => $timeout,
+            CURLOPT_USERAGENT      => $userAgent,
+            CURLOPT_FAILONERROR    => false,
+            CURLOPT_HTTPHEADER     => $requestHeaders,
+            CURLOPT_HEADERFUNCTION => function ($ch, $line) use (&$responseHeaders) {
+                $pos = strpos($line, ':');
+
+                if ($pos !== false) {
+                    $name = catalog_http_normalize_header_name(substr($line, 0, $pos));
+                    $value = trim(substr($line, $pos + 1));
+                    $responseHeaders[$name] = $value;
+                }
+
+                return strlen($line);
+            },
+        ));
+
+        $body = curl_exec($ch);
+
+        if ($body === false) {
+            $err = curl_error($ch);
+            curl_close($ch);
+            throw new RuntimeException('Catalogus ophalen mislukt: ' . $err);
+        }
+
+        $status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+        curl_close($ch);
+
+        if ($status !== 304 && ($status < 200 || $status >= 300)) {
+            throw new RuntimeException('Catalogus gaf HTTP status ' . $status . ' voor ' . $url);
+        }
+
+        return array(
+            'status' => $status,
+            'headers' => $responseHeaders,
+            'body' => $body,
+        );
+    }
+
+    $headerLines = array('User-Agent: ' . $userAgent);
+
+    foreach ($requestHeaders as $header) {
+        $headerLines[] = $header;
+    }
+
+    $ctx = stream_context_create(array(
+        'http' => array(
+            'method' => 'GET',
+            'timeout' => $timeout,
+            'header' => implode("\r\n", $headerLines) . "\r\n",
+            'ignore_errors' => true,
+        ),
+    ));
+
+    $body = @file_get_contents($url, false, $ctx);
+
+    if ($body === false) {
+        throw new RuntimeException('Catalogus ophalen mislukt: ' . $url);
+    }
+
+    $status = 0;
+    $responseHeaders = array();
+    $rawHeaders = isset($http_response_header) && is_array($http_response_header)
+        ? $http_response_header
+        : array();
+
+    foreach ($rawHeaders as $line) {
+        if (preg_match('/^HTTP\/\S+\s+(\d+)/', $line, $m)) {
+            $status = (int)$m[1];
+            continue;
+        }
+
+        $pos = strpos($line, ':');
+
+        if ($pos !== false) {
+            $name = catalog_http_normalize_header_name(substr($line, 0, $pos));
+            $value = trim(substr($line, $pos + 1));
+            $responseHeaders[$name] = $value;
+        }
+    }
+
+    if ($status !== 304 && ($status < 200 || $status >= 300)) {
+        throw new RuntimeException('Catalogus gaf HTTP status ' . $status . ' voor ' . $url);
+    }
+
+    return array(
+        'status' => $status,
+        'headers' => $responseHeaders,
+        'body' => $body,
+    );
+}
+
+function catalog_http_fetch_cached($url, $cacheFile, $metaFile, $ttl, $userAgent, $timeout = 180)
+{
+    catalog_http_ensure_dir(dirname($cacheFile));
+
+    if (is_file($cacheFile)) {
+        $mtime = filemtime($cacheFile);
+
+        if ($mtime !== false && $mtime >= time() - $ttl) {
+            $data = file_get_contents($cacheFile);
+
+            if ($data !== false && $data !== '') {
+                return $data;
+            }
+        }
+    }
+
+    $meta = catalog_http_read_meta($metaFile);
+    $requestHeaders = is_file($cacheFile) ? catalog_http_validator_headers($meta) : array();
+    $response = catalog_http_fetch($url, $requestHeaders, $userAgent, $timeout);
+
+    if ($response['status'] === 304) {
+        $data = file_get_contents($cacheFile);
+
+        if ($data !== false && $data !== '') {
+            touch($cacheFile);
+            $meta['checked_at'] = time();
+            catalog_http_write_meta($metaFile, $meta);
+            return $data;
+        }
+    }
+
+    $data = $response['body'];
+
+    if (file_put_contents($cacheFile, $data, LOCK_EX) === false) {
+        throw new RuntimeException('Kan catalogus-cache niet schrijven: ' . $cacheFile);
+    }
+
+    $headers = $response['headers'];
+    $now = time();
+    $meta = array(
+        'url' => $url,
+        'fetched_at' => $now,
+        'checked_at' => $now,
+    );
+
+    if (!empty($headers['etag'])) {
+        $meta['etag'] = $headers['etag'];
+    }
+
+    if (!empty($headers['last-modified'])) {
+        $meta['last_modified'] = $headers['last-modified'];
+    }
+
+    catalog_http_write_meta($metaFile, $meta);
+
+    return $data;
+}
diff --git a/lib/racket-data.php b/lib/racket-data.php
new file mode 100644
index 0000000..d7b8f48
--- /dev/null
+++ b/lib/racket-data.php
@@ -0,0 +1,317 @@
+<?php
+
+function rktd_package_name_ok($name)
+{
+    return is_string($name) && preg_match('/^[A-Za-z0-9_.+-]+$/', $name);
+}
+
+function rktd_unescape_string($s)
+{
+    $out = '';
+    $n = strlen($s);
+
+    for ($i = 0; $i < $n; $i++) {
+        $c = $s[$i];
+
+        if ($c !== '\\') {
+            $out .= $c;
+            continue;
+        }
+
+        if ($i + 1 >= $n) {
+            break;
+        }
+
+        $i++;
+        $e = $s[$i];
+
+        if ($e === 'n') {
+            $out .= "\n";
+        } elseif ($e === 'r') {
+            $out .= "\r";
+        } elseif ($e === 't') {
+            $out .= "\t";
+        } else {
+            $out .= $e;
+        }
+    }
+
+    return $out;
+}
+
+function rktd_read_string($s, &$i)
+{
+    $n = strlen($s);
+
+    if ($i >= $n || $s[$i] !== '"') {
+        return null;
+    }
+
+    $i++;
+    $out = '';
+
+    while ($i < $n) {
+        $c = $s[$i];
+        $i++;
+
+        if ($c === '"') {
+            return $out;
+        }
+
+        if ($c === '\\') {
+            if ($i >= $n) {
+                break;
+            }
+
+            $e = $s[$i];
+            $i++;
+
+            if ($e === 'n') {
+                $out .= "\n";
+            } elseif ($e === 'r') {
+                $out .= "\r";
+            } elseif ($e === 't') {
+                $out .= "\t";
+            } else {
+                $out .= $e;
+            }
+        } else {
+            $out .= $c;
+        }
+    }
+
+    return null;
+}
+
+function rktd_skip_space($s, &$i)
+{
+    $n = strlen($s);
+
+    while ($i < $n) {
+        $c = $s[$i];
+
+        if ($c === ';') {
+            while ($i < $n && $s[$i] !== "\n") {
+                $i++;
+            }
+            continue;
+        }
+
+        if ($c === ' ' || $c === "\t" || $c === "\r" || $c === "\n") {
+            $i++;
+            continue;
+        }
+
+        break;
+    }
+}
+
+function rktd_skip_string($s, &$i)
+{
+    $dummy = rktd_read_string($s, $i);
+    return $dummy !== null;
+}
+
+function rktd_skip_atom($s, &$i)
+{
+    $n = strlen($s);
+
+    while ($i < $n) {
+        $c = $s[$i];
+
+        if ($c === ' ' || $c === "\t" || $c === "\r" || $c === "\n" ||
+            $c === '(' || $c === ')' || $c === '"' || $c === ';') {
+            break;
+        }
+
+        $i++;
+    }
+}
+
+function rktd_skip_expr($s, &$i)
+{
+    $n = strlen($s);
+
+    rktd_skip_space($s, $i);
+
+    if ($i >= $n) {
+        return;
+    }
+
+    $c = $s[$i];
+
+    if ($c === '"') {
+        rktd_skip_string($s, $i);
+        return;
+    }
+
+    if ($c === "'") {
+        $i++;
+        rktd_skip_expr($s, $i);
+        return;
+    }
+
+    if ($c === '#') {
+        if (substr($s, $i, 2) === '#(') {
+            $i++;
+            rktd_skip_expr($s, $i);
+            return;
+        }
+
+        if (substr($s, $i, 5) === '#hash' ||
+            substr($s, $i, 7) === '#hasheq' ||
+            substr($s, $i, 8) === '#hasheqv') {
+            while ($i < $n && $s[$i] !== '(') {
+                $i++;
+            }
+            rktd_skip_expr($s, $i);
+            return;
+        }
+    }
+
+    if ($c === '(') {
+        $depth = 0;
+
+        while ($i < $n) {
+            $c = $s[$i];
+
+            if ($c === '"') {
+                rktd_skip_string($s, $i);
+                continue;
+            }
+
+            if ($c === ';') {
+                while ($i < $n && $s[$i] !== "\n") {
+                    $i++;
+                }
+                continue;
+            }
+
+            if ($c === '(') {
+                $depth++;
+                $i++;
+                continue;
+            }
+
+            if ($c === ')') {
+                $depth--;
+                $i++;
+
+                if ($depth <= 0) {
+                    return;
+                }
+
+                continue;
+            }
+
+            $i++;
+        }
+
+        return;
+    }
+
+    rktd_skip_atom($s, $i);
+}
+
+function rktd_extract_top_level_package_names($text)
+{
+    $names = array();
+
+    $i = strpos($text, '#hash');
+
+    if ($i === false) {
+        $i = strpos($text, '#hasheq');
+    }
+
+    if ($i === false) {
+        $i = strpos($text, '#hasheqv');
+    }
+
+    if ($i === false) {
+        return array();
+    }
+
+    $n = strlen($text);
+
+    while ($i < $n && $text[$i] !== '(') {
+        $i++;
+    }
+
+    if ($i >= $n || $text[$i] !== '(') {
+        return array();
+    }
+
+    $i++;
+
+    while ($i < $n) {
+        rktd_skip_space($text, $i);
+
+        if ($i >= $n) {
+            break;
+        }
+
+        if ($text[$i] === ')') {
+            break;
+        }
+
+        if ($text[$i] !== '(') {
+            $i++;
+            continue;
+        }
+
+        $i++;
+        rktd_skip_space($text, $i);
+        $name = rktd_read_string($text, $i);
+
+        if ($name === null) {
+            while ($i < $n && $text[$i] !== ')') {
+                rktd_skip_expr($text, $i);
+                rktd_skip_space($text, $i);
+            }
+
+            if ($i < $n && $text[$i] === ')') {
+                $i++;
+            }
+
+            continue;
+        }
+
+        if (rktd_package_name_ok($name)) {
+            $names[$name] = true;
+        }
+
+        rktd_skip_space($text, $i);
+
+        if ($i < $n && $text[$i] === '.') {
+            $i++;
+        }
+
+        rktd_skip_expr($text, $i);
+        rktd_skip_space($text, $i);
+
+        if ($i < $n && $text[$i] === ')') {
+            $i++;
+        }
+    }
+
+    $out = array_keys($names);
+    sort($out, SORT_NATURAL | SORT_FLAG_CASE);
+
+    return $out;
+}
+
+function rktd_extract_catalog_source($catalogText)
+{
+    $patterns = array(
+        '/\\(\\s*source\\s*\\.\\s*"((?:[^"\\\\]|\\\\.)*)"\\s*\\)/s',
+        '/\\(\\s*"source"\\s*\\.\\s*"((?:[^"\\\\]|\\\\.)*)"\\s*\\)/s',
+    );
+
+    foreach ($patterns as $pat) {
+        if (preg_match($pat, $catalogText, $m)) {
+            return rktd_unescape_string($m[1]);
+        }
+    }
+
+    return null;
+}
diff --git a/login.php b/login.php
new file mode 100644
index 0000000..9ae3950
--- /dev/null
+++ b/login.php
@@ -0,0 +1,143 @@
+<?php
+/*
+ * login.php
+ */
+
+require_once __DIR__ . '/auth.php';
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+$auth = new RacketSandboxAuth(__DIR__ . '/data/racket-sandbox.sqlite');
+
+$error = '';
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function detect_login_language($supported, $fallback)
+{
+    $header = $_SERVER['HTTP_ACCEPT_LANGUAGE'] ?? '';
+    $preferences = array();
+
+    foreach (explode(',', $header) as $part) {
+        $pieces = array_map('trim', explode(';', $part));
+        $lang = strtolower($pieces[0] ?? '');
+        $quality = 1.0;
+
+        foreach (array_slice($pieces, 1) as $piece) {
+            if (strpos($piece, 'q=') === 0) {
+                $quality = (float)substr($piece, 2);
+            }
+        }
+
+        if ($lang !== '') {
+            $preferences[] = array('lang' => $lang, 'quality' => $quality);
+        }
+    }
+
+    usort($preferences, function ($a, $b) {
+        return $a['quality'] < $b['quality'] ? 1 : -1;
+    });
+
+    foreach ($preferences as $preference) {
+        $lang = $preference['lang'];
+        $primary = explode('-', $lang, 2)[0];
+
+        if (isset($supported[$lang])) {
+            return $lang;
+        }
+
+        if (isset($supported[$primary])) {
+            return $primary;
+        }
+    }
+
+    return $fallback;
+}
+
+$pageTitle = 'Racket ChatGPT Agent Sandbox Creator';
+$texts = array(
+    'en' => array(
+        'email' => 'Email address',
+        'password' => 'Password',
+        'login' => 'Login',
+        'account_title' => 'Want to try it?',
+        'account_text' => 'If you would like an account to try the sandbox, please request one from Hans Dijkema through the Racket Discourse pages.',
+        'account_link' => 'Go to Racket Discourse',
+    ),
+    'nl' => array(
+        'email' => 'E-mailadres',
+        'password' => 'Wachtwoord',
+        'login' => 'Inloggen',
+        'account_title' => 'Wil je het eens proberen?',
+        'account_text' => 'Als je een account wilt om de sandbox eens uit te proberen, doe dan een verzoek aan Hans Dijkema via de Racket Discourse-pagina\'s.',
+        'account_link' => 'Naar Racket Discourse',
+    ),
+);
+$language = detect_login_language($texts, 'en');
+$styleVersion = @filemtime(__DIR__ . '/styles.css') ?: time();
+
+if ($auth->currentUser() !== null && $_SERVER['REQUEST_METHOD'] !== 'POST') {
+    header('Location: /');
+    exit;
+}
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    try {
+        $auth->login($_POST['email'] ?? '', $_POST['password'] ?? '');
+        header('Location: /');
+        exit;
+    } catch (Throwable $e) {
+        $error = $e->getMessage();
+    }
+}
+
+header('Content-Type: text/html; charset=utf-8');
+?>
+<!doctype html>
+<html lang="<?= h($language) ?>">
+<head>
+<meta charset="utf-8">
+<title><?= h($pageTitle) ?></title>
+<link rel="stylesheet" href="/styles.css?v=<?= h($styleVersion) ?>">
+</head>
+<body class="simple-doc login-page">
+
+<main class="login-layout">
+<section class="login-panel">
+<h1><?= h($pageTitle) ?></h1>
+
+<?php if ($error !== ''): ?>
+<div class="error"><?= h($error) ?></div>
+<?php endif; ?>
+
+<form method="post" action="/login.php">
+
+<label>
+<?= h($texts[$language]['email']) ?><br>
+<input type="email" name="email" autocomplete="username" required>
+</label>
+
+<label>
+<?= h($texts[$language]['password']) ?><br>
+<input type="password" name="password" autocomplete="current-password" required>
+</label>
+
+<button type="submit"><?= h($texts[$language]['login']) ?></button>
+</form>
+</section>
+
+<aside class="login-request-panel">
+<h2><?= h($texts[$language]['account_title']) ?></h2>
+<p><?= h($texts[$language]['account_text']) ?></p>
+<p><a href="https://racket.discourse.group/"><?= h($texts[$language]['account_link']) ?></a></p>
+</aside>
+</main>
+
+</body>
+</html>
diff --git a/make-user.php b/make-user.php
new file mode 100644
index 0000000..b7a718b
--- /dev/null
+++ b/make-user.php
@@ -0,0 +1,52 @@
+<?php
+/*
+ * make-user.php
+ *
+ * CLI tool om handmatig gebruikers aan te maken.
+ *
+ * Gebruik:
+ *
+ *   php make-user.php <email> "<full name>" <password> <admin:0|1>
+ *
+ * Voorbeeld:
+ *
+ *   php make-user.php hans@example.nl "Hans Dijkema" "lang-genoeg-wachtwoord" 1
+ */
+
+require_once __DIR__ . '/auth.php';
+
+if (PHP_SAPI !== 'cli') {
+    echo "CLI only\n";
+    exit(1);
+}
+
+if ($argc < 5) {
+    echo "Usage:\n";
+    echo "  php make-user.php <email> \"<full name>\" <password> <admin:0|1>\n\n";
+    echo "Example:\n";
+    echo "  php make-user.php hans@example.nl \"Hans Dijkema\" \"lang-genoeg-wachtwoord\" 1\n";
+    exit(1);
+}
+
+$email = $argv[1];
+$fullName = $argv[2];
+$password = $argv[3];
+$isAdmin = $argv[4] === '1';
+
+try {
+    $auth = new RacketSandboxAuth(__DIR__ . '/data/racket-sandbox.sqlite');
+
+    $user = $auth->createUser($email, $fullName, $password, $isAdmin, true);
+
+    echo "Created user\n";
+    echo "------------\n";
+    echo "ID:        " . $user->id() . "\n";
+    echo "Email:     " . $user->email() . "\n";
+    echo "Full name: " . $user->fullName() . "\n";
+    echo "Admin:     " . ($user->isAdmin() ? "yes" : "no") . "\n";
+    echo "Enabled:   " . ($user->isEnabled() ? "yes" : "no") . "\n";
+    exit(0);
+} catch (Throwable $e) {
+    echo "Error: " . $e->getMessage() . "\n";
+    exit(1);
+}
\ No newline at end of file
diff --git a/nexttoken.php b/nexttoken.php
new file mode 100644
index 0000000..2faf2ce
--- /dev/null
+++ b/nexttoken.php
@@ -0,0 +1,355 @@
+<?php
+/*
+ * nexttoken.php
+ *
+ * Eenvoudige SQLite-backed next-token store.
+ *
+ * Model:
+ *   - Iedere gegenereerde HTML-pagina maakt één next-token.
+ *   - Alle links op die pagina gebruiken datzelfde token.
+ *   - Vervolgroutes accepteren een request alleen als next bestaat
+ *     en nog niet verlopen is.
+ *   - Het token heeft verder geen betekenis.
+ */
+
+class NextTokenException extends Exception
+{
+}
+
+class NextTokenStore
+{
+    private $db;
+    private $ttlSeconds;
+
+    public function __construct($dbFile, $ttlSeconds = 21600)
+    {
+        $this->ttlSeconds = (int)$ttlSeconds;
+
+        $dir = dirname($dbFile);
+        if (!is_dir($dir)) {
+            if (!mkdir($dir, 0700, true)) {
+                throw new NextTokenException('Could not create token db dir: ' . $dir);
+            }
+        }
+
+        $this->db = new PDO('sqlite:' . $dbFile);
+        $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+        $this->db->exec('PRAGMA journal_mode = WAL');
+        $this->db->exec('PRAGMA busy_timeout = 5000');
+
+        $this->init();
+    }
+
+    private function init()
+    {
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS next_tokens (
+                token TEXT PRIMARY KEY,
+                created_at INTEGER NOT NULL,
+                expires_at INTEGER NOT NULL
+            )'
+        );
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_next_tokens_expires
+             ON next_tokens(expires_at)'
+        );
+
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS next_token_words (
+                word TEXT NOT NULL,
+                kind TEXT NOT NULL,
+                language TEXT NOT NULL,
+                PRIMARY KEY(word, kind, language)
+            )'
+        );
+
+        $this->migrateTokenWordsTable();
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_next_token_words_kind
+             ON next_token_words(kind, language)'
+        );
+
+        $this->seedWords();
+    }
+
+    private function migrateTokenWordsTable()
+    {
+        $stmt = $this->db->query('PRAGMA table_info(next_token_words)');
+        $pkCols = array();
+
+        foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
+            if ((int)$row['pk'] > 0) {
+                $pkCols[(int)$row['pk']] = $row['name'];
+            }
+        }
+
+        ksort($pkCols);
+
+        if (array_values($pkCols) === array('word', 'kind', 'language')) {
+            return;
+        }
+
+        $this->db->beginTransaction();
+
+        try {
+            $this->db->exec(
+                'CREATE TABLE next_token_words_new (
+                    word TEXT NOT NULL,
+                    kind TEXT NOT NULL,
+                    language TEXT NOT NULL,
+                    PRIMARY KEY(word, kind, language)
+                )'
+            );
+
+            $this->db->exec(
+                'INSERT OR IGNORE INTO next_token_words_new (word, kind, language)
+                 SELECT word, kind, language
+                 FROM next_token_words'
+            );
+
+            $this->db->exec('DROP TABLE next_token_words');
+            $this->db->exec('ALTER TABLE next_token_words_new RENAME TO next_token_words');
+            $this->db->commit();
+        } catch (Throwable $e) {
+            if ($this->db->inTransaction()) {
+                $this->db->rollBack();
+            }
+
+            throw $e;
+        }
+    }
+
+    public function create($ttlSeconds = null)
+    {
+        $ttl = $ttlSeconds === null ? $this->ttlSeconds : (int)$ttlSeconds;
+
+        if ($ttl <= 0) {
+            throw new NextTokenException('Invalid ttl.');
+        }
+
+        $this->cleanup();
+
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO next_tokens (token, created_at, expires_at)
+             VALUES (:token, :created_at, :expires_at)'
+        );
+
+        for ($i = 0; $i < 25; $i++) {
+            $token = $this->newToken();
+
+            try {
+                $stmt->execute(array(
+                    ':token' => $token,
+                    ':created_at' => $now,
+                    ':expires_at' => $now + $ttl,
+                ));
+
+                return $token;
+            } catch (PDOException $e) {
+                if ($e->getCode() !== '23000') {
+                    throw $e;
+                }
+            }
+        }
+
+        throw new NextTokenException('Could not create unique next token.');
+    }
+
+    public function isValid($token)
+    {
+        if (!is_string($token) || !preg_match('/^[a-z0-9-]{5,160}$/', $token)) {
+            return false;
+        }
+
+        $stmt = $this->db->prepare(
+            'SELECT expires_at
+             FROM next_tokens
+             WHERE token = :token'
+        );
+
+        $stmt->execute(array(':token' => $token));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            return false;
+        }
+
+        return time() <= (int)$row['expires_at'];
+    }
+
+    public function requireValid($token)
+    {
+        if (!$this->isValid($token)) {
+            throw new NextTokenException('Invalid or expired next token.');
+        }
+
+        return true;
+    }
+
+    public function cleanup()
+    {
+        $stmt = $this->db->prepare(
+            'DELETE FROM next_tokens
+             WHERE expires_at < :now'
+        );
+
+        $stmt->execute(array(':now' => time()));
+        return $stmt->rowCount();
+    }
+
+    public function currentTokens()
+    {
+        $stmt = $this->db->prepare(
+            'SELECT token, created_at, expires_at
+             FROM next_tokens
+             WHERE expires_at >= :now
+             ORDER BY expires_at ASC, created_at ASC'
+        );
+
+        $stmt->execute(array(':now' => time()));
+        return $stmt->fetchAll(PDO::FETCH_ASSOC);
+    }
+
+    public function tokens()
+    {
+        $stmt = $this->db->query(
+            'SELECT token, created_at, expires_at
+             FROM next_tokens
+             ORDER BY expires_at ASC, created_at ASC'
+        );
+
+        return $stmt->fetchAll(PDO::FETCH_ASSOC);
+    }
+
+    public function expired_html_response()
+    {   
+        html_response('<!doctype html>
+                      <html lang="en">
+                      <head>
+                        <meta charset="utf-8">
+                        <title>Expired link</title>
+                      </head>
+                      <body>
+                      <h1>Expired or unauthorized link</h1>
+                      <p>
+                        This link is no longer valid. Please ask the human user for a new
+                        bootstrap link and restart the process from that link.
+                      </p>
+                      <p>
+                        For the AI agent: do not try to invent a new <code>next</code> value.
+                        Only follow links that appear on authorized HTML pages.
+                      </p>
+                     </body>
+                     </html>', 200);
+    }
+
+    public function expired_text_response()
+    {
+      text_response(
+        "Expired or unauthorized link.\n" .
+        "Please ask the human user for a new bootstrap link.\n" .
+        "Do not invent a new next value; only follow links from authorized HTML pages.\n",
+        200
+      );
+    }
+
+    public function expired_response($kind = 'html')
+    {
+        if ($kind === 'html') {
+            $this->expired_html_response();
+        } else {
+            $this->expired_text_response();
+        }
+    }
+
+    public function check_valid_next($kind = 'html')
+    {
+        try {
+            $this->requireValid($_GET['next'] ?? '');
+        } catch (Throwable $e) {
+            $this->expired_response($kind);
+        }
+    }
+
+    private function newToken()
+    {
+        $adjective = $this->randomWord('adjective');
+        $noun = $this->randomWord('noun');
+
+        return $adjective . '-' . $noun;
+    }
+
+    private function randomWord($kind)
+    {
+        $stmt = $this->db->prepare(
+            'SELECT word
+             FROM next_token_words
+             WHERE kind = :kind
+             ORDER BY RANDOM()
+             LIMIT 1'
+        );
+        $stmt->execute(array(':kind' => $kind));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            throw new NextTokenException('No token words available for: ' . $kind);
+        }
+
+        return (string)$row['word'];
+    }
+
+    private function seedWords()
+    {
+        $wordsFile = __DIR__ . '/config/next-token-words.php';
+
+        if (!is_file($wordsFile)) {
+            throw new NextTokenException('Next token word seed file not found.');
+        }
+
+        $words = require $wordsFile;
+
+        if (!is_array($words)) {
+            throw new NextTokenException('Invalid next token word seed file.');
+        }
+
+        $stmt = $this->db->prepare(
+            'INSERT OR IGNORE INTO next_token_words
+             (word, kind, language)
+             VALUES (:word, :kind, :language)'
+        );
+
+        foreach ($words as $language => $byKind) {
+            if (!is_array($byKind)) {
+                continue;
+            }
+
+            foreach ($byKind as $kind => $list) {
+                if ($kind !== 'adjective' && $kind !== 'noun') {
+                    continue;
+                }
+
+                if (!is_array($list)) {
+                    continue;
+                }
+
+                foreach ($list as $word) {
+                    $word = trim((string)$word);
+
+                    if (!preg_match('/^[a-z0-9-]+$/', $word)) {
+                        continue;
+                    }
+
+                    $stmt->execute(array(
+                        ':word' => $word,
+                        ':kind' => $kind,
+                        ':language' => $language,
+                    ));
+                }
+            }
+        }
+    }
+}
diff --git a/package.php b/package.php
new file mode 100644
index 0000000..febc320
--- /dev/null
+++ b/package.php
@@ -0,0 +1,476 @@
+<?php
+/*
+ * package.php
+ *
+ * Vereist:
+ *
+ *   gitfetcher.php
+ *   b64parts.php
+ *
+ * Routes:
+ *
+ *   /package?name=<package>&next=...
+ *      HTML-pagina met base64 part-links voor data/<package>.zip.
+ *
+ *   /package-part?name=<package>&part=000001&next=...
+ *      text/plain met base64-inhoud van één part.
+ *
+ * Regels:
+ *
+ *   - HTML voor index/pagina's.
+ *   - text/plain voor payload.
+ *   - Payload is altijd base64.
+ *   - Eén next-id per gegenereerde HTML-pagina.
+ */
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+require_once __DIR__ . '/nexttoken.php';
+
+$TOKENS = new NextTokenStore(__DIR__ . '/data/racket-sandbox.sqlite');
+
+@set_time_limit(300);
+ignore_user_abort(false);
+
+require_once __DIR__ . '/gitfetcher.php';
+require_once __DIR__ . '/b64parts.php';
+require_once __DIR__ . '/base64config.php';
+require_once __DIR__ . '/lib/catalog-http.php';
+require_once __DIR__ . '/lib/racket-data.php';
+
+define('DATA_DIR', __DIR__ . '/data');
+define('CATALOG_PACKAGE_BASE', 'https://pkgs.racket-lang.org/pkg/');
+define('CATALOG_CACHE_TTL', 3600);
+
+$chunkConfig = load_base64_chunk_config();
+$packageZipMaxBase64Kb = (int)($chunkConfig['package_zip_max_base64_kb'] ?? 2048);
+
+if ($packageZipMaxBase64Kb < 1) {
+    $packageZipMaxBase64Kb = 1;
+}
+
+define('PACKAGE_ZIP_MAX_BASE64_KB', $packageZipMaxBase64Kb);
+define('PACKAGE_ZIP_MAX_BASE64_BYTES', PACKAGE_ZIP_MAX_BASE64_KB * 1024);
+
+$NEXT_ID = $TOKENS->create();
+
+function path_only()
+{
+    $p = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH);
+    $p = '/' . trim($p ?: '/', '/');
+    return $p === '/' ? '/' : $p;
+}
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function current_scheme()
+{
+    if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
+        return strtolower(trim(explode(',', $_SERVER['HTTP_X_FORWARDED_PROTO'])[0]));
+    }
+
+    return (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https' : 'http';
+}
+
+function current_host()
+{
+    return $_SERVER['HTTP_HOST'] ?? 'localhost';
+}
+
+function make_url($path, $query = array())
+{
+    global $NEXT_ID;
+
+    $query['next'] = $NEXT_ID;
+
+    return current_scheme() . '://' . current_host() . $path . '?' . http_build_query($query);
+}
+
+function html_response($html, $status = 200)
+{
+    http_response_code($status);
+    header('Content-Type: text/html; charset=utf-8');
+    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
+    header('Pragma: no-cache');
+    echo $html;
+    exit;
+}
+
+function text_response($text, $status = 200)
+{
+    http_response_code($status);
+    header('Content-Type: text/plain; charset=us-ascii');
+    header('Content-Disposition: inline');
+    header('X-Content-Type-Options: nosniff');
+    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
+    header('Pragma: no-cache');
+
+    echo $text;
+
+    if ($text === '' || substr($text, -1) !== "\n") {
+        echo "\n";
+    }
+
+    exit;
+}
+
+function fail_html($message, $status = 500)
+{
+    html_response(
+        '<!doctype html><html><head><meta charset="utf-8">' .
+        '<title>Package error</title></head><body>' .
+        '<h1>Package error</h1>' .
+        '<pre>' . h($message) . '</pre>' .
+        '</body></html>',
+        $status
+    );
+}
+
+function fail_text($message, $status = 500)
+{
+    text_response("error: " . $message . "\n", $status);
+}
+
+function package_name_ok($name)
+{
+    return rktd_package_name_ok($name);
+}
+
+function ensure_data_dir()
+{
+    try {
+        catalog_http_ensure_dir(DATA_DIR);
+    } catch (Throwable $e) {
+        fail_html($e->getMessage());
+    }
+}
+
+function catalog_cache_file($package)
+{
+    ensure_data_dir();
+    return DATA_DIR . '/catalog-' . sha1($package) . '.rktd';
+}
+
+function catalog_meta_file($package)
+{
+    ensure_data_dir();
+    return DATA_DIR . '/catalog-' . sha1($package) . '.meta.json';
+}
+
+function get_catalog_package_text($package)
+{
+    $cacheFile = catalog_cache_file($package);
+    $url = CATALOG_PACKAGE_BASE . rawurlencode($package);
+
+    try {
+        return catalog_http_fetch_cached(
+            $url,
+            $cacheFile,
+            catalog_meta_file($package),
+            CATALOG_CACHE_TTL,
+            'rktsndbx-package-entry/1.0',
+            180
+        );
+    } catch (Throwable $e) {
+        fail_html($e->getMessage());
+    }
+}
+
+function extract_catalog_source($catalogText)
+{
+    return rktd_extract_catalog_source($catalogText);
+}
+
+function normalize_source_to_repo_url($source)
+{
+    $source = trim((string)$source);
+
+    if ($source === '') {
+        fail_html('Lege package source.');
+    }
+
+    /*
+     * github://github.com/owner/repo[/branch[/subdir]]
+     * Voor nu gebruiken we owner/repo. Subdirs lossen we later op.
+     */
+    $p = parse_url($source);
+
+    if ($p === false || empty($p['scheme'])) {
+        fail_html('Kan package source niet parsen: ' . $source);
+    }
+
+    $scheme = strtolower($p['scheme']);
+
+    if ($scheme === 'github') {
+        $host = !empty($p['host']) ? strtolower($p['host']) : 'github.com';
+        $path = trim($p['path'] ?? '', '/');
+        $bits = explode('/', $path);
+
+        if ($host !== 'github.com' || count($bits) < 2) {
+            fail_html('Ongeldige github package source: ' . $source);
+        }
+
+        return 'https://github.com/' . $bits[0] . '/' . $bits[1];
+    }
+
+    /*
+     * git+https://... normaliseren. gitfetcher.php kan hier ook deels mee
+     * omgaan, maar dit houdt metadata netter.
+     */
+    if (strpos($source, 'git+https://') === 0) {
+        return 'https://' . substr($source, strlen('git+https://'));
+    }
+
+    if (strpos($source, 'git+http://') === 0) {
+        return 'http://' . substr($source, strlen('git+http://'));
+    }
+
+    /*
+     * Verwijder query/fragment voor de repository-fetch.
+     * ?path=... en #branch/subdir pakken we later apart aan.
+     */
+    $source = preg_replace('/[?#].*$/', '', $source);
+
+    return $source;
+}
+
+function ensure_package_zip_and_parts($package)
+{
+    $catalogText = get_catalog_package_text($package);
+    $source = extract_catalog_source($catalogText);
+
+    if ($source === null || $source === '') {
+        fail_html('Geen source gevonden in Racket package catalogus voor package: ' . $package);
+    }
+
+    $repoUrl = normalize_source_to_repo_url($source);
+
+    $fetcher = new GitFetcher(array(
+        'data_dir' => DATA_DIR,
+    ));
+
+    try {
+        $zipInfo = $fetcher->ensurePackageZip($package, $repoUrl);
+    } catch (Throwable $e) {
+        fail_html(
+            "Kon package zip niet ophalen.\n\n" .
+            "Package: " . $package . "\n" .
+            "Catalog source: " . $source . "\n" .
+            "Repo URL: " . $repoUrl . "\n\n" .
+            $e->getMessage()
+        );
+    }
+
+    $zipFile = DATA_DIR . '/' . $package . '.zip';
+
+    if (!is_file($zipFile) || !is_readable($zipFile)) {
+        fail_html('Zipbestand ontbreekt na fetch: ' . $zipFile);
+    }
+
+    $parts = new Base64Parts(DATA_DIR, PACKAGE_ZIP_MAX_BASE64_BYTES);
+
+    try {
+        $manifest = ensure_parts_for_zip($parts, $package, $zipFile);
+    } catch (Throwable $e) {
+        fail_html('Kon base64-parts niet maken: ' . $e->getMessage());
+    }
+
+    return array(
+        'package'  => $package,
+        'source'   => $source,
+        'repo_url' => $repoUrl,
+        'zip_info' => $zipInfo,
+        'manifest' => $manifest,
+    );
+}
+
+function ensure_parts_for_zip($parts, $package, $zipFile)
+{
+    $zipSha = hash_file('sha256', $zipFile);
+    $zipSize = filesize($zipFile);
+
+    /*
+     * Hergebruik bestaande parts als ze nog exact bij de zip horen.
+     */
+    try {
+        $manifest = $parts->loadManifest($package);
+
+        if (isset($manifest['source_sha256']) &&
+            $manifest['source_sha256'] === $zipSha &&
+            isset($manifest['source_bytes']) &&
+            (int)$manifest['source_bytes'] === (int)$zipSize &&
+            isset($manifest['max_base64_bytes']) &&
+            (int)$manifest['max_base64_bytes'] === PACKAGE_ZIP_MAX_BASE64_BYTES &&
+            isset($manifest['parts']) &&
+            is_array($manifest['parts']) &&
+            count($manifest['parts']) > 0) {
+
+            $ok = true;
+
+            foreach ($manifest['parts'] as $part) {
+                if (empty($part['file']) || !is_file($part['file']) || !is_readable($part['file'])) {
+                    $ok = false;
+                    break;
+                }
+            }
+
+            if ($ok) {
+                $manifest['parts_status'] = 'cached';
+                return $manifest;
+            }
+        }
+    } catch (Throwable $e) {
+        /*
+         * Geen manifest of ongeldig manifest: gewoon opnieuw maken.
+         */
+    }
+
+    $manifest = $parts->splitFile($zipFile, $package, true);
+    $manifest['parts_status'] = 'created';
+
+    return $manifest;
+}
+
+function serve_package_page()
+{
+    global $NEXT_ID;
+
+    $package = $_GET['name'] ?? '';
+
+    if (!package_name_ok($package)) {
+        fail_html('Ongeldige of ontbrekende package naam.', 400);
+    }
+
+    $info = ensure_package_zip_and_parts($package);
+
+    $manifest = $info['manifest'];
+    $zipInfo = $info['zip_info'];
+
+    $rows = '';
+
+    foreach ($manifest['parts'] as $part) {
+        $n = $part['number'];
+
+        $url = make_url('/package-part', array(
+            'name' => $package,
+            'part' => $n,
+        ));
+
+        $rows .=
+            '<tr>' .
+            '<td>' . h($n) . '</td>' .
+            '<td>' . h((string)$part['base64_bytes']) . '</td>' .
+            '<td><a href="' . h($url) . '">' . h($url) . '</a></td>' .
+            '</tr>' . "\n";
+    }
+
+    html_response('<!doctype html>
+<html lang="nl">
+<head>
+<meta charset="utf-8">
+<title>Package ' . h($package) . '</title>
+<link rel="stylesheet" href="/styles.css">
+</head>
+<body class="simple-doc">
+
+<h1>Package ' . h($package) . '</h1>
+
+<p>
+Deze pagina is HTML. Alle part-links hieronder geven <code>text/plain</code>
+met base64-inhoud terug. Dezelfde <code>next</code> wordt gebruikt voor alle
+part-links op deze pagina.
+</p>
+
+<h2>Bron</h2>
+
+<table>
+<tr><th>catalog source</th><td><code>' . h($info['source']) . '</code></td></tr>
+<tr><th>repo url</th><td><code>' . h($info['repo_url']) . '</code></td></tr>
+<tr><th>fetch status</th><td><code>' . h($zipInfo['status'] ?? '') . '</code></td></tr>
+<tr><th>default branch</th><td><code>' . h($zipInfo['default_branch'] ?? '') . '</code></td></tr>
+<tr><th>head sha</th><td><code>' . h($zipInfo['head_sha'] ?? '') . '</code></td></tr>
+<tr><th>zip file</th><td><code>' . h($zipInfo['zip_file'] ?? '') . '</code></td></tr>
+<tr><th>zip bytes</th><td><code>' . h((string)($zipInfo['zip_bytes'] ?? '')) . '</code></td></tr>
+<tr><th>zip sha256</th><td><code>' . h($zipInfo['zip_sha256'] ?? '') . '</code></td></tr>
+<tr><th>parts status</th><td><code>' . h($manifest['parts_status'] ?? '') . '</code></td></tr>
+<tr><th>max base64 part size</th><td><code>' . h((string)PACKAGE_ZIP_MAX_BASE64_KB) . '</code> KiB (<code>' . h((string)PACKAGE_ZIP_MAX_BASE64_BYTES) . '</code> bytes)</td></tr>
+<tr><th>binary chunk size</th><td><code>' . h((string)($manifest['binary_chunk_bytes'] ?? '')) . '</code> bytes</td></tr>
+<tr><th>part count</th><td><code>' . h((string)$manifest['part_count']) . '</code></td></tr>
+<tr><th>next id</th><td><code>' . h($NEXT_ID) . '</code></td></tr>
+</table>
+
+<h2>Base64 parts</h2>
+
+<table>
+<thead>
+<tr>
+<th>part</th>
+<th>base64 bytes</th>
+<th>text/plain URL</th>
+</tr>
+</thead>
+<tbody>
+' . $rows . '
+</tbody>
+</table>
+
+<h2>Reconstructie in de sandbox</h2>
+
+<pre>
+# download alle links als:
+# ' . h($package) . '.part.000001.b64
+# ' . h($package) . '.part.000002.b64
+# enz.
+
+cat ' . h($package) . '.part.*.b64 &gt; ' . h($package) . '.zip.b64
+base64 -d ' . h($package) . '.zip.b64 &gt; ' . h($package) . '.zip
+raco pkg install --auto ./' . h($package) . '.zip
+</pre>
+
+</body>
+</html>');
+}
+
+function serve_package_part()
+{
+    $package = $_GET['name'] ?? '';
+    $part = $_GET['part'] ?? '';
+
+    if (!package_name_ok($package)) {
+        fail_text('Ongeldige of ontbrekende package naam.', 400);
+    }
+
+    if (!is_string($part) || !preg_match('/^[0-9]{6}$/', $part)) {
+        fail_text('Ongeldig of ontbrekend partnummer.', 400);
+    }
+
+    $parts = new Base64Parts(DATA_DIR, PACKAGE_ZIP_MAX_BASE64_BYTES);
+
+    try {
+        $txt = $parts->readPart($package, $part);
+    } catch (Throwable $e) {
+        fail_text($e->getMessage(), 404);
+    }
+
+    text_response($txt, 200);
+}
+
+$path = path_only();
+
+if ($path === '/package') {
+    $TOKENS->check_valid_next('html');
+    serve_package_page();
+}
+
+if ($path === '/package-part') {
+    $TOKENS->check_valid_next('text');
+    serve_package_part();
+}
+
+fail_html('Onbekende route: ' . $path, 404);
diff --git a/prompt-editor.js b/prompt-editor.js
new file mode 100644
index 0000000..f7f3bea
--- /dev/null
+++ b/prompt-editor.js
@@ -0,0 +1,516 @@
+(function () {
+    'use strict';
+
+    let promptData = { personal: {}, default: {}, can_edit_defaults: false };
+    let currentKind = null;
+    let currentPrompt = null;
+    let currentVersions = [];
+    let versionIndex = 0;
+    let uiText = {
+        prompt_not_found: 'Prompt not found',
+        no_previous_versions: 'No previous versions stored.',
+        no_lines_for_view: 'No lines for this view.',
+        restore_version_confirm: 'Restore version',
+        delete_version_confirm: 'Delete version',
+        default_prompt_prefix: 'Default prompt: ',
+        prompt_prefix: 'Prompt: ',
+        created: 'created',
+        updated: 'updated',
+        default_prompt: 'default prompt',
+        version: 'version',
+        showing_version: 'showing version',
+        of: 'of',
+        old: 'old',
+        new: 'new'
+    };
+
+    function byId(id) {
+        return document.getElementById(id);
+    }
+
+    function readPromptData() {
+        const el = byId('promptDataJson');
+        const textEl = byId('promptTextJson');
+
+        if (!el) {
+            return;
+        }
+
+        try {
+            promptData = JSON.parse(el.textContent || '{}');
+        } catch (e) {
+            console.error('Could not parse prompt data JSON', e);
+            promptData = { personal: {}, default: {} };
+        }
+
+        if (!textEl) {
+            return;
+        }
+
+        try {
+            uiText = Object.assign(uiText, JSON.parse(textEl.textContent || '{}'));
+        } catch (e) {
+            console.error('Could not parse prompt text JSON', e);
+        }
+    }
+
+    function esc(s) {
+        return String(s)
+            .replaceAll('&', '&amp;')
+            .replaceAll('<', '&lt;')
+            .replaceAll('>', '&gt;')
+            .replaceAll('"', '&quot;')
+            .replaceAll("'", '&#039;');
+    }
+
+    function fmtTs(ts) {
+        if (!ts) {
+            return '-';
+        }
+
+        const d = new Date(ts * 1000);
+        return d.toISOString().replace('T', ' ').slice(0, 19);
+    }
+
+    function promptActionUrl(kind) {
+        const url = new URL(window.location.href);
+        url.pathname = '/prompts';
+        url.searchParams.set('mode', kind === 'default' ? 'defaults' : 'personal');
+        return url.pathname + url.search;
+    }
+
+    function setEditing(editing) {
+        const shell = byId('promptModalForm');
+        const mayEdit = currentKind !== 'default' || promptData.can_edit_defaults;
+        editing = editing && mayEdit;
+
+        shell.classList.toggle('edit-mode', editing);
+        shell.classList.toggle('can-edit', mayEdit);
+        shell.classList.toggle('read-only-default', currentKind === 'default' && !mayEdit);
+
+        byId('modalName').readOnly = !editing;
+        byId('modalContent').readOnly = !editing;
+        byId('modalDefaultKey').readOnly = !editing;
+        byId('modalLanguage').disabled = !editing;
+    }
+
+    function openEditModal() {
+        if (!currentPrompt) {
+            return;
+        }
+
+        if (currentKind === 'default' && !promptData.can_edit_defaults) {
+            return;
+        }
+
+        setEditing(true);
+        byId('promptModalBackdrop').classList.add('open');
+        renderVersionPane();
+    }
+
+    function closeEditModal() {
+        byId('promptModalBackdrop').classList.remove('open');
+        if (currentPrompt) {
+            resetEditorFields();
+            renderVersionPane();
+        }
+    }
+
+    function resetEditorFields() {
+        byId('modalName').value = currentPrompt.name;
+        byId('modalLanguage').value = currentPrompt.language;
+        byId('modalContent').value = currentPrompt.content;
+        byId('modalDefaultKey').value = currentPrompt.default_key || '';
+        setEditing(false);
+    }
+
+    function openPromptEditor(kind, id) {
+        currentKind = kind;
+        currentPrompt = promptData[kind] ? promptData[kind][id] : null;
+
+        if (!currentPrompt) {
+            alert(uiText.prompt_not_found);
+            return;
+        }
+
+        currentVersions = currentPrompt.versions || [];
+        currentVersions.sort(function (a, b) {
+            return b.version_no - a.version_no;
+        });
+
+        /*
+         * The newest stored version is often the current snapshot. If possible,
+         * start by showing the one before that.
+         */
+        versionIndex = currentVersions.length > 1 ? 1 : 0;
+
+        byId('modalTitle').textContent =
+            (kind === 'default' ? uiText.default_prompt_prefix : uiText.prompt_prefix) +
+            currentPrompt.name;
+        byId('viewerTitle').textContent =
+            (kind === 'default' ? uiText.default_prompt_prefix : uiText.prompt_prefix) +
+            currentPrompt.name;
+
+        byId('modalMeta').textContent =
+            uiText.created + ' ' + fmtTs(currentPrompt.created_at) +
+            ' · ' + uiText.updated + ' ' + fmtTs(currentPrompt.updated_at) +
+            (kind === 'default' && !promptData.can_edit_defaults ? ' · ' + uiText.default_prompt : '');
+        byId('viewerMeta').textContent = byId('modalMeta').textContent;
+        byId('viewerContent').textContent = currentPrompt.content;
+
+        byId('defaultKeyRow').style.display = kind === 'default' ? 'block' : 'none';
+
+        if (kind === 'default') {
+            byId('modalAction').value = 'update_default';
+            byId('modalDefaultId').value = currentPrompt.id;
+            byId('modalPromptId').value = '';
+        } else {
+            byId('modalAction').value = 'update_prompt';
+            byId('modalPromptId').value = currentPrompt.id;
+            byId('modalDefaultId').value = '';
+        }
+
+        byId('promptModalForm').action = promptActionUrl(kind);
+        byId('modalAuxForm').action = promptActionUrl(kind);
+
+        byId('promptViewer').classList.remove('is-empty');
+        byId('promptViewer').classList.toggle('is-default-prompt', kind === 'default');
+        byId('promptModalBackdrop').classList.toggle('is-default-prompt', kind === 'default');
+        byId('editPromptButton').style.display =
+            kind === 'default' && !promptData.can_edit_defaults ? 'none' : '';
+        document.querySelectorAll('.prompt-select').forEach(function (button) {
+            button.classList.toggle(
+                'selected',
+                button.dataset.kind === kind && button.dataset.id === String(id)
+            );
+        });
+
+        resetEditorFields();
+        renderVersionPane();
+    }
+
+    function currentSelectedVersion() {
+        if (currentVersions.length === 0) {
+            return null;
+        }
+
+        if (versionIndex < 0) {
+            versionIndex = 0;
+        }
+
+        if (versionIndex >= currentVersions.length) {
+            versionIndex = currentVersions.length - 1;
+        }
+
+        return currentVersions[versionIndex];
+    }
+
+    function olderVersion() {
+        if (currentVersions.length === 0) {
+            return;
+        }
+
+        if (versionIndex < currentVersions.length - 1) {
+            versionIndex++;
+            renderVersionPane();
+        }
+    }
+
+    function newerVersion() {
+        if (currentVersions.length === 0) {
+            return;
+        }
+
+        const minIndex = currentVersions.length > 1 ? 1 : 0;
+
+        if (versionIndex > minIndex) {
+            versionIndex--;
+            renderVersionPane();
+        }
+    }
+
+    function renderVersionPane() {
+        const version = currentSelectedVersion();
+        const contentEl = byId('versionContent');
+        const metaEl = byId('selectedVersionMeta');
+        const indicatorEl = byId('versionIndicator');
+
+        if (!version) {
+            contentEl.innerHTML = '<span class="diff-muted">' +
+                esc(uiText.no_previous_versions) +
+                '</span>';
+            metaEl.textContent = '';
+            indicatorEl.textContent = '';
+            return;
+        }
+
+        metaEl.textContent =
+            uiText.version + ' ' + version.version_no +
+            ' · ' + fmtTs(version.created_at) +
+            (version.note ? ' · ' + version.note : '');
+
+        indicatorEl.textContent =
+            uiText.showing_version + ' ' + version.version_no +
+            ' (' + (versionIndex + 1) + ' ' + uiText.of + ' ' + currentVersions.length + ')';
+
+        const currentText = byId('modalContent').value;
+        const oldText = version.content;
+        const mode = byId('diffMode').value;
+
+        if (mode === 'plain') {
+            contentEl.innerHTML = esc(oldText);
+            return;
+        }
+
+        contentEl.innerHTML = renderLineDiff(oldText, currentText, mode);
+    }
+
+    function linesOf(s) {
+        return String(s).split(/\r?\n/);
+    }
+
+    function lcsTable(a, b) {
+        const m = a.length;
+        const n = b.length;
+        const dp = Array.from({ length: m + 1 }, function () {
+            return Array(n + 1).fill(0);
+        });
+
+        for (let i = m - 1; i >= 0; i--) {
+            for (let j = n - 1; j >= 0; j--) {
+                if (a[i] === b[j]) {
+                    dp[i][j] = dp[i + 1][j + 1] + 1;
+                } else {
+                    dp[i][j] = Math.max(dp[i + 1][j], dp[i][j + 1]);
+                }
+            }
+        }
+
+        return dp;
+    }
+
+    function diffOps(oldLines, newLines) {
+        const dp = lcsTable(oldLines, newLines);
+        const ops = [];
+        let i = 0;
+        let j = 0;
+
+        while (i < oldLines.length && j < newLines.length) {
+            if (oldLines[i] === newLines[j]) {
+                ops.push({ type: 'same', oldLine: oldLines[i], newLine: newLines[j] });
+                i++;
+                j++;
+            } else if (dp[i + 1][j] >= dp[i][j + 1]) {
+                ops.push({ type: 'deleted', oldLine: oldLines[i] });
+                i++;
+            } else {
+                ops.push({ type: 'added', newLine: newLines[j] });
+                j++;
+            }
+        }
+
+        while (i < oldLines.length) {
+            ops.push({ type: 'deleted', oldLine: oldLines[i] });
+            i++;
+        }
+
+        while (j < newLines.length) {
+            ops.push({ type: 'added', newLine: newLines[j] });
+            j++;
+        }
+
+        return pairChangedLines(ops);
+    }
+
+    function pairChangedLines(ops) {
+        const paired = [];
+
+        for (let k = 0; k < ops.length; k++) {
+            const a = ops[k];
+            const b = ops[k + 1];
+
+            if (a && b && a.type === 'deleted' && b.type === 'added') {
+                paired.push({
+                    type: 'changed',
+                    oldLine: a.oldLine,
+                    newLine: b.newLine
+                });
+                k++;
+            } else if (a && b && a.type === 'added' && b.type === 'deleted') {
+                paired.push({
+                    type: 'changed',
+                    oldLine: b.oldLine,
+                    newLine: a.newLine
+                });
+                k++;
+            } else {
+                paired.push(a);
+            }
+        }
+
+        return paired;
+    }
+
+    function renderLineDiff(oldText, newText, mode) {
+        const ops = diffOps(linesOf(oldText), linesOf(newText));
+        const out = [];
+
+        for (const op of ops) {
+            if (mode !== 'all' && mode !== op.type) {
+                continue;
+            }
+
+            if (op.type === 'same') {
+                out.push('<span class="diff-line diff-same">' + esc(op.oldLine) + '</span>');
+            } else if (op.type === 'added') {
+                out.push('<span class="diff-line diff-added">+ ' + esc(op.newLine) + '</span>');
+            } else if (op.type === 'deleted') {
+                out.push('<span class="diff-line diff-deleted">- ' + esc(op.oldLine) + '</span>');
+            } else if (op.type === 'changed') {
+                out.push(
+                    '<span class="diff-line diff-changed">~ ' +
+                    esc(uiText.old) +
+                    ': ' +
+                    esc(op.oldLine) +
+                    '</span>'
+                );
+                out.push(
+                    '<span class="diff-line diff-changed">~ ' +
+                    esc(uiText.new) +
+                    ': ' +
+                    esc(op.newLine) +
+                    '</span>'
+                );
+            }
+        }
+
+        if (out.length === 0) {
+            return '<span class="diff-muted">' + esc(uiText.no_lines_for_view) + '</span>';
+        }
+
+        return out.join('');
+    }
+
+    function configureAux(action, versionNo) {
+        const aux = byId('modalAuxForm');
+
+        byId('auxAction').value = action;
+        byId('auxVersionNo').value = versionNo || '';
+        byId('auxVersionNote').value = 'modal snapshot';
+
+        if (currentKind === 'default') {
+            byId('auxDefaultId').value = currentPrompt.id;
+            byId('auxPromptId').value = '';
+        } else {
+            byId('auxPromptId').value = currentPrompt.id;
+            byId('auxDefaultId').value = '';
+        }
+
+        return aux;
+    }
+
+    function storeSnapshot() {
+        if (!currentPrompt) {
+            return;
+        }
+
+        const action = currentKind === 'default'
+            ? 'create_default_version'
+            : 'create_version';
+
+        configureAux(action, '').submit();
+    }
+
+    function restoreSelectedVersion() {
+        const version = currentSelectedVersion();
+
+        if (!currentPrompt || !version) {
+            return;
+        }
+
+        if (!confirm(uiText.restore_version_confirm + ' ' + version.version_no + '?')) {
+            return;
+        }
+
+        const action = currentKind === 'default'
+            ? 'restore_default_version'
+            : 'restore_version';
+
+        configureAux(action, version.version_no).submit();
+    }
+
+    function deleteSelectedVersion() {
+        const version = currentSelectedVersion();
+
+        if (!currentPrompt || !version) {
+            return;
+        }
+
+        if (!confirm(uiText.delete_version_confirm + ' ' + version.version_no + '?')) {
+            return;
+        }
+
+        const action = currentKind === 'default'
+            ? 'delete_default_version'
+            : 'delete_version';
+
+        configureAux(action, version.version_no).submit();
+    }
+
+    function bindEvents() {
+        document.querySelectorAll('.prompt-tab').forEach(function (tab) {
+            tab.addEventListener('click', function () {
+                const tabName = tab.dataset.tab;
+
+                document.querySelectorAll('.prompt-tab').forEach(function (other) {
+                    const active = other === tab;
+                    other.classList.toggle('active', active);
+                    other.setAttribute('aria-selected', active ? 'true' : 'false');
+                });
+
+                document.querySelectorAll('.prompt-tab-panel').forEach(function (panel) {
+                    panel.classList.toggle('active', panel.id === 'tab-' + tabName);
+                });
+            });
+        });
+
+        document.querySelectorAll('.js-open-prompt').forEach(function (button) {
+            button.addEventListener('click', function () {
+                openPromptEditor(button.dataset.kind, button.dataset.id);
+            });
+        });
+
+        byId('editPromptButton').addEventListener('click', function () {
+            openEditModal();
+        });
+        byId('cancelEditButton').addEventListener('click', function () {
+            closeEditModal();
+        });
+        byId('versionNewerButton').addEventListener('click', newerVersion);
+        byId('versionOlderButton').addEventListener('click', olderVersion);
+        byId('diffMode').addEventListener('change', renderVersionPane);
+        byId('modalContent').addEventListener('input', renderVersionPane);
+        byId('snapshotButton').addEventListener('click', storeSnapshot);
+        byId('restoreVersionButton').addEventListener('click', restoreSelectedVersion);
+        byId('deleteVersionButton').addEventListener('click', deleteSelectedVersion);
+
+        byId('promptModalBackdrop').addEventListener('click', function (ev) {
+            if (ev.target === byId('promptModalBackdrop')) {
+                closeEditModal();
+            }
+        });
+
+        document.addEventListener('keydown', function (ev) {
+            if (ev.key === 'Escape') {
+                closeEditModal();
+            }
+        });
+
+        setEditing(false);
+    }
+
+    document.addEventListener('DOMContentLoaded', function () {
+        readPromptData();
+        bindEvents();
+    });
+}());
diff --git a/prompts.php b/prompts.php
new file mode 100644
index 0000000..2603b35
--- /dev/null
+++ b/prompts.php
@@ -0,0 +1,720 @@
+<?php
+/*
+ * prompts.php
+ *
+ * User/admin prompt administration page.
+ *
+ * Normal users:
+ *   - manage personal prompts
+ *   - copy global default prompts to their own prompts
+ *
+ * Admin users:
+ *   - same as normal users
+ *   - manage global default prompts
+ */
+
+require_once __DIR__ . '/auth.php';
+require_once __DIR__ . '/header.php';
+require_once __DIR__ . '/languagestore.php';
+require_once __DIR__ . '/promptstore.php';
+require_once __DIR__ . '/usersettings.php';
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+$DB_FILE = __DIR__ . '/data/racket-sandbox.sqlite';
+
+$auth = new RacketSandboxAuth($DB_FILE);
+$user = $auth->requireLoginHtml();
+
+$store = new PromptStore($DB_FILE);
+$languageStore = new LanguageStore($DB_FILE);
+$userSettings = new UserSettingsStore($DB_FILE);
+
+$message = '';
+$error = '';
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function t($key, $fallback = null)
+{
+    global $languageStore, $language;
+
+    return $languageStore->translate($key, $language, $fallback);
+}
+
+function post_value($name, $default = '')
+{
+    return $_POST[$name] ?? $default;
+}
+
+function get_value($name, $default = '')
+{
+    return $_GET[$name] ?? $default;
+}
+
+function fmt_time($ts)
+{
+    if ($ts === null) {
+        return '-';
+    }
+
+    return date('Y-m-d H:i:s', (int)$ts);
+}
+
+function prompt_to_array($prompt)
+{
+    return array(
+        'id' => $prompt->id(),
+        'name' => $prompt->name(),
+        'language' => $prompt->language(),
+        'content' => $prompt->content(),
+        'default_key' => $prompt->defaultKey(),
+        'is_default' => $prompt->isDefault(),
+        'created_at' => $prompt->createdAt(),
+        'updated_at' => $prompt->updatedAt(),
+    );
+}
+
+function version_to_array($version)
+{
+    return array(
+        'id' => $version->id(),
+        'prompt_id' => $version->promptId(),
+        'version_no' => $version->versionNo(),
+        'name' => $version->name(),
+        'language' => $version->language(),
+        'content' => $version->content(),
+        'note' => $version->note(),
+        'created_at' => $version->createdAt(),
+    );
+}
+
+function resolve_user_language($userSettings, $userId, $allowedLanguages)
+{
+    $language = isset($_GET['lang'])
+        ? (string)$_GET['lang']
+        : (string)$userSettings->get($userId, 'language', 'en');
+
+    if (!in_array($language, $allowedLanguages, true)) {
+        $language = 'en';
+    }
+
+    $userSettings->set($userId, 'language', $language);
+
+    return $language;
+}
+
+$language = resolve_user_language(
+    $userSettings,
+    $user->id(),
+    $store->supportedLanguages()
+);
+
+$languageStore->seedDefaults(array(
+    'prompts.title' => array('en' => 'Prompt administration', 'nl' => 'Promptbeheer'),
+    'prompts.back' => array('en' => 'Back to Racket sandbox', 'nl' => 'Terug naar Racket sandbox'),
+    'prompts.your_prompts' => array('en' => 'Your prompts', 'nl' => 'Jouw prompts'),
+    'prompts.default_admin' => array('en' => 'Default prompt administration', 'nl' => 'Standaardpromptbeheer'),
+    'prompts.language' => array('en' => 'Language', 'nl' => 'Taal'),
+    'prompts.available_defaults' => array('en' => 'Available default prompts', 'nl' => 'Beschikbare standaardprompts'),
+    'prompts.default_admin_badge' => array('en' => 'Admin default prompts', 'nl' => 'Admin standaardprompts'),
+    'prompts.default_admin_hint' => array(
+        'en' => 'You are editing global default prompts. Users can copy these to their own prompts.',
+        'nl' => 'Je bewerkt globale standaardprompts. Gebruikers kunnen deze naar hun eigen prompts kopieren.'
+    ),
+    'prompts.copy_all' => array('en' => 'Copy all', 'nl' => 'Alles kopieren'),
+    'prompts.copy' => array('en' => 'copy', 'nl' => 'kopieer'),
+    'prompts.delete' => array('en' => 'delete', 'nl' => 'verwijder'),
+    'prompts.create_default' => array('en' => 'Create default prompt', 'nl' => 'Standaardprompt maken'),
+    'prompts.create_personal' => array('en' => 'Create personal prompt', 'nl' => 'Persoonlijke prompt maken'),
+    'prompts.name' => array('en' => 'Name', 'nl' => 'Naam'),
+    'prompts.default_key' => array('en' => 'Default key', 'nl' => 'Standaardsleutel'),
+    'prompts.prompt_content' => array('en' => 'Prompt content', 'nl' => 'Promptinhoud'),
+    'prompts.no_defaults' => array('en' => 'No default prompts for this language yet.', 'nl' => 'Nog geen standaardprompts voor deze taal.'),
+    'prompts.no_personal' => array('en' => 'No personal prompts yet for this language.', 'nl' => 'Nog geen persoonlijke prompts voor deze taal.'),
+    'prompts.select_prompt' => array('en' => 'Select a prompt on the left to view it.', 'nl' => 'Selecteer links een prompt om deze te bekijken.'),
+    'prompts.edit' => array('en' => 'Edit', 'nl' => 'Bewerk'),
+    'prompts.close' => array('en' => 'Close', 'nl' => 'Sluiten'),
+    'prompts.newer_previous' => array('en' => 'newer previous version', 'nl' => 'nieuwere vorige versie'),
+    'prompts.older_previous' => array('en' => 'older previous version', 'nl' => 'oudere vorige versie'),
+    'prompts.diff_view' => array('en' => 'Diff view:', 'nl' => 'Verschilweergave:'),
+    'prompts.diff_plain' => array('en' => 'text, no diff', 'nl' => 'tekst, geen verschil'),
+    'prompts.diff_all' => array('en' => 'all diff', 'nl' => 'alle verschillen'),
+    'prompts.diff_same' => array('en' => 'unchanged only', 'nl' => 'alleen ongewijzigd'),
+    'prompts.diff_added' => array('en' => 'additions only', 'nl' => 'alleen toevoegingen'),
+    'prompts.diff_deleted' => array('en' => 'deletions only', 'nl' => 'alleen verwijderingen'),
+    'prompts.diff_changed' => array('en' => 'changes only', 'nl' => 'alleen wijzigingen'),
+    'prompts.previous_version' => array('en' => 'Previous version', 'nl' => 'Vorige versie'),
+    'prompts.store_version' => array('en' => 'store this edit as a new version', 'nl' => 'bewaar deze bewerking als nieuwe versie'),
+    'prompts.version_note' => array('en' => 'Version note:', 'nl' => 'Versienotitie:'),
+    'prompts.save' => array('en' => 'Save', 'nl' => 'Opslaan'),
+    'prompts.store_snapshot' => array('en' => 'Store snapshot', 'nl' => 'Snapshot bewaren'),
+    'prompts.restore_version' => array('en' => 'Restore selected version', 'nl' => 'Geselecteerde versie herstellen'),
+    'prompts.delete_version' => array('en' => 'Delete selected version', 'nl' => 'Geselecteerde versie verwijderen'),
+    'prompts.prompt' => array('en' => 'Prompt', 'nl' => 'Prompt'),
+    'prompts.prompt_not_found' => array('en' => 'Prompt not found', 'nl' => 'Prompt niet gevonden'),
+    'prompts.no_previous_versions' => array('en' => 'No previous versions stored.', 'nl' => 'Geen vorige versies opgeslagen.'),
+    'prompts.no_lines_for_view' => array('en' => 'No lines for this view.', 'nl' => 'Geen regels voor deze weergave.'),
+    'prompts.restore_version_confirm' => array('en' => 'Restore version', 'nl' => 'Versie herstellen'),
+    'prompts.delete_version_confirm' => array('en' => 'Delete version', 'nl' => 'Versie verwijderen'),
+    'prompts.delete_default_confirm' => array('en' => 'Delete default prompt', 'nl' => 'Standaardprompt verwijderen'),
+    'prompts.delete_prompt_confirm' => array('en' => 'Delete prompt', 'nl' => 'Prompt verwijderen'),
+    'prompts.default_prompt_prefix' => array('en' => 'Default prompt: ', 'nl' => 'Standaardprompt: '),
+    'prompts.prompt_prefix' => array('en' => 'Prompt: ', 'nl' => 'Prompt: '),
+    'prompts.created' => array('en' => 'created', 'nl' => 'gemaakt'),
+    'prompts.updated' => array('en' => 'updated', 'nl' => 'bijgewerkt'),
+    'prompts.default_prompt' => array('en' => 'default prompt', 'nl' => 'standaardprompt'),
+    'prompts.version' => array('en' => 'version', 'nl' => 'versie'),
+    'prompts.showing_version' => array('en' => 'showing version', 'nl' => 'toont versie'),
+    'prompts.of' => array('en' => 'of', 'nl' => 'van'),
+    'prompts.old' => array('en' => 'old', 'nl' => 'oud'),
+    'prompts.new' => array('en' => 'new', 'nl' => 'nieuw'),
+    'app.admin' => array('en' => 'admin', 'nl' => 'admin'),
+    'app.user_management' => array('en' => 'User management', 'nl' => 'Gebruikersbeheer'),
+    'app.configuration' => array('en' => 'Configuration', 'nl' => 'Configuratie'),
+    'app.logout' => array('en' => 'Logout', 'nl' => 'Uitloggen'),
+));
+
+$mode = get_value('mode', 'personal');
+
+if ($mode !== 'personal' && $mode !== 'defaults') {
+    $mode = 'personal';
+}
+
+if ($mode === 'defaults' && !$user->isAdmin()) {
+    $mode = 'personal';
+}
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    $action = post_value('action');
+
+    try {
+        /*
+         * User actions.
+         */
+        if ($action === 'logout') {
+            $auth->logout();
+            header('Location: /login.php');
+            exit;
+        } elseif ($action === 'copy_all_defaults') {
+            $language = post_value('language', 'en');
+            $created = $store->copyAllDefaultsToUser($user->id(), $language);
+            $message = 'Default prompts copied to your prompts: ' . $created;
+            $mode = 'personal';
+        } elseif ($action === 'copy_default') {
+            $defaultId = (int)post_value('default_id');
+            $store->copyDefaultPromptToUser($user->id(), $defaultId);
+            $message = 'Default prompt copied to your prompts.';
+            $mode = 'personal';
+        } elseif ($action === 'create_prompt') {
+            $language = post_value('language', 'en');
+
+            $store->createPrompt(
+                $user->id(),
+                post_value('name'),
+                $language,
+                post_value('content')
+            );
+
+            $message = 'Prompt created.';
+            $mode = 'personal';
+        } elseif ($action === 'update_prompt') {
+            $promptId = (int)post_value('prompt_id');
+            $language = post_value('language', 'en');
+
+            $store->updatePrompt(
+                $user->id(),
+                $promptId,
+                post_value('name'),
+                $language,
+                post_value('content'),
+                isset($_POST['create_version']),
+                post_value('version_note')
+            );
+
+            $message = 'Prompt updated.';
+            $mode = 'personal';
+        } elseif ($action === 'create_version') {
+            $promptId = (int)post_value('prompt_id');
+            $store->createVersion($user->id(), $promptId, post_value('version_note'));
+            $message = 'Version stored.';
+            $mode = 'personal';
+        } elseif ($action === 'restore_version') {
+            $promptId = (int)post_value('prompt_id');
+            $versionNo = (int)post_value('version_no');
+            $store->restoreVersion($user->id(), $promptId, $versionNo);
+            $message = 'Version restored.';
+            $mode = 'personal';
+        } elseif ($action === 'delete_version') {
+            $promptId = (int)post_value('prompt_id');
+            $versionNo = (int)post_value('version_no');
+            $store->deleteVersion($user->id(), $promptId, $versionNo);
+            $message = 'Version deleted.';
+            $mode = 'personal';
+        } elseif ($action === 'delete_prompt') {
+            $promptId = (int)post_value('prompt_id');
+            $store->deletePrompt($user->id(), $promptId);
+            $message = 'Prompt deleted.';
+            $mode = 'personal';
+        }
+
+        /*
+         * Admin-only default prompt actions.
+         */
+        elseif ($action === 'create_default' ||
+                $action === 'update_default' ||
+                $action === 'create_default_version' ||
+                $action === 'restore_default_version' ||
+                $action === 'delete_default_version' ||
+                $action === 'delete_default') {
+
+            if (!$user->isAdmin()) {
+                throw new Exception('Admin rights required.');
+            }
+
+            $mode = 'defaults';
+
+            if ($action === 'create_default') {
+                $language = post_value('language', 'en');
+
+                $store->createDefaultPrompt(
+                    post_value('default_key'),
+                    post_value('name'),
+                    $language,
+                    post_value('content')
+                );
+
+                $message = 'Default prompt created.';
+            } elseif ($action === 'update_default') {
+                $defaultId = (int)post_value('default_id');
+                $language = post_value('language', 'en');
+
+                $store->updateDefaultPrompt(
+                    $defaultId,
+                    post_value('default_key'),
+                    post_value('name'),
+                    $language,
+                    post_value('content'),
+                    isset($_POST['create_version']),
+                    post_value('version_note')
+                );
+
+                $message = 'Default prompt updated.';
+            } elseif ($action === 'create_default_version') {
+                $defaultId = (int)post_value('default_id');
+                $store->createDefaultVersion($defaultId, post_value('version_note'));
+                $message = 'Default prompt version stored.';
+            } elseif ($action === 'restore_default_version') {
+                $defaultId = (int)post_value('default_id');
+                $versionNo = (int)post_value('version_no');
+                $store->restoreDefaultVersion($defaultId, $versionNo);
+                $message = 'Default prompt version restored.';
+            } elseif ($action === 'delete_default_version') {
+                $defaultId = (int)post_value('default_id');
+                $versionNo = (int)post_value('version_no');
+                $store->deleteDefaultVersion($defaultId, $versionNo);
+                $message = 'Default prompt version deleted.';
+            } elseif ($action === 'delete_default') {
+                $defaultId = (int)post_value('default_id');
+                $store->deleteDefaultPrompt($defaultId);
+                $message = 'Default prompt deleted.';
+            }
+        } elseif ($action !== '') {
+            throw new Exception('Unknown action: ' . $action);
+        }
+    } catch (Throwable $e) {
+        $error = $e->getMessage();
+    }
+}
+
+$personalPrompts = $store->listPrompts($user->id(), $language);
+$defaultPrompts = $store->listDefaultPrompts($language);
+
+/*
+ * Full prompt data for the modal editor.
+ */
+$allPersonalPrompts = $store->listPrompts($user->id(), null);
+$allDefaultPrompts = $store->listDefaultPrompts(null);
+
+$promptData = array(
+    'personal' => array(),
+    'default' => array(),
+    'can_edit_defaults' => $user->isAdmin(),
+);
+
+foreach ($allPersonalPrompts as $p) {
+    $promptData['personal'][$p->id()] = prompt_to_array($p);
+    $promptData['personal'][$p->id()]['versions'] = array();
+
+    foreach ($store->listVersions($user->id(), $p->id()) as $v) {
+        $promptData['personal'][$p->id()]['versions'][] = version_to_array($v);
+    }
+}
+
+foreach ($allDefaultPrompts as $p) {
+    $promptData['default'][$p->id()] = prompt_to_array($p);
+    $promptData['default'][$p->id()]['versions'] = array();
+
+    if ($user->isAdmin()) {
+        foreach ($store->listDefaultVersions($p->id()) as $v) {
+            $promptData['default'][$p->id()]['versions'][] = version_to_array($v);
+        }
+    }
+}
+
+$headerLanguages = array();
+
+foreach ($store->supportedLanguages() as $lang) {
+    $headerLanguages[$lang] = $store->languageLabel($lang);
+}
+
+$headerNavItems = array(
+    array(
+        'label' => t('prompts.back', 'Back to Racket sandbox'),
+        'url' => '/',
+    ),
+);
+
+if ($user->isAdmin()) {
+    $headerNavItems[] = array(
+        'label' => t('app.user_management', 'User management'),
+        'url' => '/users?lang=' . rawurlencode($language),
+        'separator_before' => true,
+    );
+    $headerNavItems[] = array(
+        'label' => t('app.configuration', 'Configuration'),
+        'url' => '/admin-config?lang=' . rawurlencode($language),
+        'separator_before' => true,
+    );
+}
+
+$styleVersion = @filemtime(__DIR__ . '/styles.css') ?: time();
+$promptEditorVersion = @filemtime(__DIR__ . '/prompt-editor.js') ?: time();
+
+header('Content-Type: text/html; charset=utf-8');
+?>
+<!doctype html>
+<html lang="<?= h($language) ?>">
+<head>
+<meta charset="utf-8">
+<title><?= h(t('prompts.title', 'Prompt administration')) ?></title>
+<link rel="stylesheet" href="/styles.css?v=<?= h($styleVersion) ?>">
+</head>
+<body>
+
+<div class="page">
+
+<?php
+render_app_header(array(
+    'title' => t('prompts.title', 'Prompt administration'),
+    'nav_items' => $headerNavItems,
+    'user' => $user,
+    'admin_label' => t('app.admin', 'admin'),
+    'language_label' => t('prompts.language', 'Language'),
+    'language' => $language,
+    'languages' => $headerLanguages,
+    'language_action' => '/prompts',
+    'language_hidden' => array('mode' => $mode),
+    'logout_action' => '/prompts?lang=' . rawurlencode($language) . '&mode=' . rawurlencode($mode),
+    'logout_label' => t('app.logout', 'Logout'),
+    'message' => $message,
+    'error' => $error,
+));
+?>
+
+<main class="page-main prompt-workbench">
+
+<aside class="prompt-sidebar panel">
+<div class="prompt-tabs" role="tablist" aria-label="Prompt lists">
+<button type="button" class="prompt-tab <?= $mode === 'defaults' ? 'active' : '' ?>" data-tab="defaults" role="tab" aria-selected="<?= $mode === 'defaults' ? 'true' : 'false' ?>">
+<?= h(t('prompts.available_defaults', 'Available default prompts')) ?>
+</button>
+<button type="button" class="prompt-tab <?= $mode !== 'defaults' ? 'active' : '' ?>" data-tab="personal" role="tab" aria-selected="<?= $mode !== 'defaults' ? 'true' : 'false' ?>">
+<?= h(t('prompts.your_prompts', 'Your prompts')) ?>
+</button>
+</div>
+
+<section class="prompt-tab-panel <?= $mode === 'defaults' ? 'active' : '' ?>" id="tab-defaults" role="tabpanel">
+<?php if ($user->isAdmin()): ?>
+<div class="default-admin-notice">
+<strong><?= h(t('prompts.default_admin_badge', 'Admin default prompts')) ?></strong>
+<span><?= h(t('prompts.default_admin_hint', 'You are editing global default prompts. Users can copy these to their own prompts.')) ?></span>
+</div>
+<?php endif; ?>
+
+<div class="sidebar-actions">
+<form method="post" action="/prompts?lang=<?= h($language) ?>&mode=personal">
+<input type="hidden" name="action" value="copy_all_defaults">
+<input type="hidden" name="language" value="<?= h($language) ?>">
+<button type="submit"><?= h(t('prompts.copy_all', 'Copy all')) ?></button>
+</form>
+</div>
+
+<div class="prompt-list">
+<?php foreach ($defaultPrompts as $default): ?>
+<div class="prompt-list-item default-prompt-item">
+<button type="button"
+        class="prompt-select js-open-prompt"
+        data-kind="default"
+        data-id="<?= h($default->id()) ?>">
+<span class="prompt-name"><?= h($default->name()) ?></span>
+<span class="prompt-subline"><code><?= h($default->defaultKey()) ?></code> · <?= h(fmt_time($default->updatedAt())) ?></span>
+</button>
+
+<form method="post" action="/prompts?lang=<?= h($language) ?>&mode=personal">
+<input type="hidden" name="action" value="copy_default">
+<input type="hidden" name="default_id" value="<?= h($default->id()) ?>">
+<button type="submit"><?= h(t('prompts.copy', 'copy')) ?></button>
+</form>
+
+<?php if ($user->isAdmin()): ?>
+<form method="post" action="/prompts?lang=<?= h($language) ?>&mode=defaults"
+      onsubmit="return confirm('<?= h(t('prompts.delete_default_confirm', 'Delete default prompt')) ?> <?= h($default->name()) ?>?');">
+<input type="hidden" name="action" value="delete_default">
+<input type="hidden" name="default_id" value="<?= h($default->id()) ?>">
+<button type="submit"><?= h(t('prompts.delete', 'delete')) ?></button>
+</form>
+<?php endif; ?>
+</div>
+<?php endforeach; ?>
+
+<?php if (count($defaultPrompts) === 0): ?>
+<p class="empty-state"><?= h(t('prompts.no_defaults', 'No default prompts for this language yet.')) ?></p>
+<?php endif; ?>
+</div>
+
+<?php if ($user->isAdmin()): ?>
+<details class="create-drawer">
+<summary><?= h(t('prompts.create_default', 'Create default prompt')) ?></summary>
+<form method="post" action="/prompts?lang=<?= h($language) ?>&mode=defaults">
+<input type="hidden" name="action" value="create_default">
+<label><?= h(t('prompts.default_key', 'Default key')) ?><br><input type="text" name="default_key" placeholder="bootstrap-racket"></label>
+<label><?= h(t('prompts.name', 'Name')) ?><br><input type="text" name="name"></label>
+<label><?= h(t('prompts.language', 'Language')) ?><br>
+<select name="language">
+<?php foreach ($store->supportedLanguages() as $lang): ?>
+<option value="<?= h($lang) ?>" <?= $lang === $language ? 'selected' : '' ?>>
+<?= h($store->languageLabel($lang)) ?>
+</option>
+<?php endforeach; ?>
+</select>
+</label>
+<label><?= h(t('prompts.prompt_content', 'Prompt content')) ?><br><textarea name="content" rows="7"></textarea></label>
+<button type="submit"><?= h(t('prompts.create_default', 'Create default prompt')) ?></button>
+</form>
+</details>
+<?php endif; ?>
+</section>
+
+<section class="prompt-tab-panel <?= $mode !== 'defaults' ? 'active' : '' ?>" id="tab-personal" role="tabpanel">
+<div class="prompt-list">
+<?php foreach ($personalPrompts as $prompt): ?>
+<div class="prompt-list-item">
+<button type="button"
+        class="prompt-select js-open-prompt"
+        data-kind="personal"
+        data-id="<?= h($prompt->id()) ?>">
+<span class="prompt-name"><?= h($prompt->name()) ?></span>
+<span class="prompt-subline"><?= h($store->languageLabel($prompt->language())) ?> · <?= h(fmt_time($prompt->updatedAt())) ?></span>
+</button>
+<form method="post" action="/prompts?lang=<?= h($language) ?>&mode=personal"
+      onsubmit="return confirm('<?= h(t('prompts.delete_prompt_confirm', 'Delete prompt')) ?> <?= h($prompt->name()) ?>?');">
+<input type="hidden" name="action" value="delete_prompt">
+<input type="hidden" name="prompt_id" value="<?= h($prompt->id()) ?>">
+<button type="submit"><?= h(t('prompts.delete', 'delete')) ?></button>
+</form>
+</div>
+<?php endforeach; ?>
+
+<?php if (count($personalPrompts) === 0): ?>
+<p class="empty-state"><?= h(t('prompts.no_personal', 'No personal prompts yet for this language.')) ?></p>
+<?php endif; ?>
+</div>
+
+<details class="create-drawer">
+<summary><?= h(t('prompts.create_personal', 'Create personal prompt')) ?></summary>
+<form method="post" action="/prompts?lang=<?= h($language) ?>&mode=personal">
+<input type="hidden" name="action" value="create_prompt">
+<label><?= h(t('prompts.name', 'Name')) ?><br><input type="text" name="name"></label>
+<label><?= h(t('prompts.language', 'Language')) ?><br>
+<select name="language">
+<?php foreach ($store->supportedLanguages() as $lang): ?>
+<option value="<?= h($lang) ?>" <?= $lang === $language ? 'selected' : '' ?>>
+<?= h($store->languageLabel($lang)) ?>
+</option>
+<?php endforeach; ?>
+</select>
+</label>
+<label><?= h(t('prompts.prompt_content', 'Prompt content')) ?><br><textarea name="content" rows="7"></textarea></label>
+<button type="submit"><?= h(t('prompts.create_personal', 'Create prompt')) ?></button>
+</form>
+</details>
+</section>
+</aside>
+
+<section id="promptViewer" class="prompt-viewer panel is-empty">
+<div class="viewer-empty">
+<?= h(t('prompts.select_prompt', 'Select a prompt on the left to view it.')) ?>
+</div>
+
+<div class="viewer-shell">
+<div class="viewer-header">
+<div>
+<div class="viewer-title" id="viewerTitle"><?= h(t('prompts.prompt', 'Prompt')) ?></div>
+<div class="version-meta" id="viewerMeta"></div>
+</div>
+<button type="button" id="editPromptButton"><?= h(t('prompts.edit', 'Edit')) ?></button>
+</div>
+<pre id="viewerContent" class="viewer-content"></pre>
+</div>
+</section>
+
+</main>
+
+<footer class="page-footer">
+<a href="/"><?= h(t('prompts.back', 'Back to Racket sandbox')) ?></a>
+</footer>
+
+</div>
+
+<div id="promptModalBackdrop" class="modal-backdrop">
+<div class="prompt-modal">
+
+<form id="promptModalForm" class="edit-mode" method="post" action="/prompts?lang=<?= h($language) ?>&mode=<?= h($mode) ?>">
+
+<div class="modal-header">
+<div>
+<div class="modal-title" id="modalTitle"><?= h(t('prompts.prompt', 'Prompt')) ?></div>
+<div class="version-meta" id="modalMeta"></div>
+</div>
+<button type="button" id="cancelEditButton"><?= h(t('prompts.close', 'Close')) ?></button>
+</div>
+
+<div class="modal-toolbar">
+<button type="button" id="versionNewerButton"><?= h(t('prompts.newer_previous', 'newer previous version')) ?></button>
+<button type="button" id="versionOlderButton"><?= h(t('prompts.older_previous', 'older previous version')) ?></button>
+
+<label>
+<?= h(t('prompts.diff_view', 'Diff view:')) ?>
+<select id="diffMode">
+<option value="plain"><?= h(t('prompts.diff_plain', 'text, no diff')) ?></option>
+<option value="all" selected><?= h(t('prompts.diff_all', 'all diff')) ?></option>
+<option value="same"><?= h(t('prompts.diff_same', 'unchanged only')) ?></option>
+<option value="added"><?= h(t('prompts.diff_added', 'additions only')) ?></option>
+<option value="deleted"><?= h(t('prompts.diff_deleted', 'deletions only')) ?></option>
+<option value="changed"><?= h(t('prompts.diff_changed', 'changes only')) ?></option>
+</select>
+</label>
+
+<span id="versionIndicator" class="version-meta"></span>
+</div>
+
+<div class="modal-body">
+
+<div class="edit-pane">
+<div class="modal-form-grid">
+<label>
+<?= h(t('prompts.name', 'Name')) ?><br>
+<input type="text" id="modalName" name="name">
+</label>
+
+<label>
+<?= h(t('prompts.language', 'Language')) ?><br>
+<select id="modalLanguage" name="language">
+<?php foreach ($store->supportedLanguages() as $lang): ?>
+<option value="<?= h($lang) ?>"><?= h($store->languageLabel($lang)) ?></option>
+<?php endforeach; ?>
+</select>
+</label>
+</div>
+
+<div id="defaultKeyRow" class="default-key-row">
+<label>
+<?= h(t('prompts.default_key', 'Default key')) ?><br>
+<input type="text" id="modalDefaultKey" name="default_key">
+</label>
+</div>
+
+<label class="content-label">
+<span><?= h(t('prompts.prompt_content', 'Prompt content')) ?></span>
+<textarea id="modalContent" name="content"></textarea>
+</label>
+</div>
+
+<div class="version-pane">
+<div>
+<strong><?= h(t('prompts.previous_version', 'Previous version')) ?></strong>
+<div id="selectedVersionMeta" class="version-meta"></div>
+</div>
+
+<div class="version-content" id="versionContent"></div>
+</div>
+
+</div>
+
+<div class="modal-footer">
+<input type="hidden" id="modalAction" name="action" value="">
+<input type="hidden" id="modalPromptId" name="prompt_id" value="">
+<input type="hidden" id="modalDefaultId" name="default_id" value="">
+
+<label>
+<input type="checkbox" name="create_version" value="1" checked>
+<?= h(t('prompts.store_version', 'store this edit as a new version')) ?>
+</label>
+
+<label>
+<?= h(t('prompts.version_note', 'Version note:')) ?>
+<input type="text" name="version_note" value="editor edit">
+</label>
+
+<button type="submit"><?= h(t('prompts.save', 'Save')) ?></button>
+<button type="button" id="snapshotButton"><?= h(t('prompts.store_snapshot', 'Store snapshot')) ?></button>
+<button type="button" id="restoreVersionButton"><?= h(t('prompts.restore_version', 'Restore selected version')) ?></button>
+<button type="button" id="deleteVersionButton"><?= h(t('prompts.delete_version', 'Delete selected version')) ?></button>
+</div>
+
+</form>
+
+</div>
+</div>
+
+<form id="modalAuxForm" method="post" action="/prompts?lang=<?= h($language) ?>&mode=<?= h($mode) ?>" class="hidden">
+<input type="hidden" id="auxAction" name="action" value="">
+<input type="hidden" id="auxPromptId" name="prompt_id" value="">
+<input type="hidden" id="auxDefaultId" name="default_id" value="">
+<input type="hidden" id="auxVersionNo" name="version_no" value="">
+<input type="hidden" id="auxVersionNote" name="version_note" value="">
+</form>
+
+<script type="application/json" id="promptDataJson">
+<?= json_encode($promptData, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) ?>
+</script>
+<script type="application/json" id="promptTextJson">
+<?= json_encode(array(
+    'prompt_not_found' => t('prompts.prompt_not_found', 'Prompt not found'),
+    'no_previous_versions' => t('prompts.no_previous_versions', 'No previous versions stored.'),
+    'no_lines_for_view' => t('prompts.no_lines_for_view', 'No lines for this view.'),
+    'restore_version_confirm' => t('prompts.restore_version_confirm', 'Restore version'),
+    'delete_version_confirm' => t('prompts.delete_version_confirm', 'Delete version'),
+    'default_prompt_prefix' => t('prompts.default_prompt_prefix', 'Default prompt: '),
+    'prompt_prefix' => t('prompts.prompt_prefix', 'Prompt: '),
+    'created' => t('prompts.created', 'created'),
+    'updated' => t('prompts.updated', 'updated'),
+    'default_prompt' => t('prompts.default_prompt', 'default prompt'),
+    'version' => t('prompts.version', 'version'),
+    'showing_version' => t('prompts.showing_version', 'showing version'),
+    'of' => t('prompts.of', 'of'),
+    'old' => t('prompts.old', 'old'),
+    'new' => t('prompts.new', 'new'),
+), JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) ?>
+</script>
+<script src="/prompt-editor.js?v=<?= h($promptEditorVersion) ?>" defer></script>
+
+</body>
+</html>
diff --git a/promptstore.php b/promptstore.php
new file mode 100644
index 0000000..9ca09ad
--- /dev/null
+++ b/promptstore.php
@@ -0,0 +1,1075 @@
+<?php
+/*
+ * promptstore.php
+ *
+ * Prompt storage for Racket sandbox.
+ *
+ * Supports:
+ *   - personal user prompts
+ *   - global default prompts managed by admins
+ *   - prompt versions
+ *   - automatic SQLite migration
+ *
+ * Database:
+ *   data/racket-sandbox.sqlite
+ *
+ * Model:
+ *   user_id = 0 and is_default = 1:
+ *     global default prompt
+ *
+ *   user_id > 0 and is_default = 0:
+ *     personal user prompt
+ */
+
+class PromptStoreException extends Exception
+{
+}
+
+class PromptRecord
+{
+    private $row;
+
+    public function __construct($row)
+    {
+        $this->row = is_array($row) ? $row : array();
+    }
+
+    public function id()
+    {
+        return (int)($this->row['id'] ?? 0);
+    }
+
+    public function userId()
+    {
+        return (int)($this->row['user_id'] ?? 0);
+    }
+
+    public function isDefault()
+    {
+        return (int)($this->row['is_default'] ?? 0) === 1;
+    }
+
+    public function defaultKey()
+    {
+        return (string)($this->row['default_key'] ?? '');
+    }
+
+    public function name()
+    {
+        return (string)($this->row['name'] ?? '');
+    }
+
+    public function language()
+    {
+        return (string)($this->row['language'] ?? '');
+    }
+
+    public function content()
+    {
+        return (string)($this->row['content'] ?? '');
+    }
+
+    public function createdAt()
+    {
+        return isset($this->row['created_at']) ? (int)$this->row['created_at'] : null;
+    }
+
+    public function updatedAt()
+    {
+        return isset($this->row['updated_at']) ? (int)$this->row['updated_at'] : null;
+    }
+
+    public function deletedAt()
+    {
+        return isset($this->row['deleted_at']) && $this->row['deleted_at'] !== null
+            ? (int)$this->row['deleted_at']
+            : null;
+    }
+
+    public function raw()
+    {
+        return $this->row;
+    }
+}
+
+class PromptVersionRecord
+{
+    private $row;
+
+    public function __construct($row)
+    {
+        $this->row = is_array($row) ? $row : array();
+    }
+
+    public function id()
+    {
+        return (int)($this->row['id'] ?? 0);
+    }
+
+    public function promptId()
+    {
+        return (int)($this->row['prompt_id'] ?? 0);
+    }
+
+    public function userId()
+    {
+        return (int)($this->row['user_id'] ?? 0);
+    }
+
+    public function versionNo()
+    {
+        return (int)($this->row['version_no'] ?? 0);
+    }
+
+    public function name()
+    {
+        return (string)($this->row['name'] ?? '');
+    }
+
+    public function language()
+    {
+        return (string)($this->row['language'] ?? '');
+    }
+
+    public function content()
+    {
+        return (string)($this->row['content'] ?? '');
+    }
+
+    public function note()
+    {
+        return (string)($this->row['note'] ?? '');
+    }
+
+    public function createdAt()
+    {
+        return isset($this->row['created_at']) ? (int)$this->row['created_at'] : null;
+    }
+
+    public function raw()
+    {
+        return $this->row;
+    }
+}
+
+class PromptStore
+{
+    private $db;
+
+    public function __construct($dbFile)
+    {
+        $dir = dirname($dbFile);
+
+        if (!is_dir($dir)) {
+            if (!mkdir($dir, 0700, true)) {
+                throw new PromptStoreException('Could not create database directory: ' . $dir);
+            }
+        }
+
+        $this->db = new PDO('sqlite:' . $dbFile);
+        $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+        $this->db->exec('PRAGMA journal_mode = WAL');
+        $this->db->exec('PRAGMA busy_timeout = 5000');
+
+        $this->init();
+    }
+
+    private function init()
+    {
+        /*
+         * Canonical schema.
+         *
+         * Existing databases are migrated below. In particular, this version
+         * does not require nullable user_id. Global defaults use user_id = 0.
+         */
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS prompts (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                user_id INTEGER NOT NULL DEFAULT 0,
+                is_default INTEGER NOT NULL DEFAULT 0,
+                default_key TEXT NULL,
+                name TEXT NOT NULL,
+                language TEXT NOT NULL,
+                content TEXT NOT NULL,
+                created_at INTEGER NOT NULL,
+                updated_at INTEGER NOT NULL,
+                deleted_at INTEGER NULL
+            )'
+        );
+
+        $this->migratePromptsTable();
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_prompts_user
+             ON prompts(user_id, is_default, deleted_at, language, name)'
+        );
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_prompts_default
+             ON prompts(is_default, deleted_at, language, default_key)'
+        );
+
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS prompt_versions (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                prompt_id INTEGER NOT NULL,
+                user_id INTEGER NOT NULL DEFAULT 0,
+                version_no INTEGER NOT NULL,
+                name TEXT NOT NULL,
+                language TEXT NOT NULL,
+                content TEXT NOT NULL,
+                note TEXT NOT NULL DEFAULT "",
+                created_at INTEGER NOT NULL,
+                FOREIGN KEY(prompt_id) REFERENCES prompts(id),
+                UNIQUE(prompt_id, version_no)
+            )'
+        );
+
+        $this->migratePromptVersionsTable();
+
+        $this->db->exec(
+            'CREATE INDEX IF NOT EXISTS idx_prompt_versions_prompt
+             ON prompt_versions(prompt_id, version_no)'
+        );
+    }
+
+    private function migratePromptsTable()
+    {
+        $cols = $this->tableColumns('prompts');
+
+        if (!isset($cols['user_id'])) {
+            $this->db->exec('ALTER TABLE prompts ADD COLUMN user_id INTEGER NOT NULL DEFAULT 0');
+        }
+
+        if (!isset($cols['is_default'])) {
+            $this->db->exec('ALTER TABLE prompts ADD COLUMN is_default INTEGER NOT NULL DEFAULT 0');
+        }
+
+        if (!isset($cols['default_key'])) {
+            $this->db->exec('ALTER TABLE prompts ADD COLUMN default_key TEXT NULL');
+        }
+
+        if (!isset($cols['deleted_at'])) {
+            $this->db->exec('ALTER TABLE prompts ADD COLUMN deleted_at INTEGER NULL');
+        }
+
+        /*
+         * Normalize existing rows.
+         */
+        $this->db->exec(
+            'UPDATE prompts
+             SET is_default = 0
+             WHERE is_default IS NULL'
+        );
+
+        $this->db->exec(
+            'UPDATE prompts
+             SET user_id = 0
+             WHERE is_default = 1'
+        );
+    }
+
+    private function migratePromptVersionsTable()
+    {
+        $cols = $this->tableColumns('prompt_versions');
+
+        if (!isset($cols['user_id'])) {
+            $this->db->exec('ALTER TABLE prompt_versions ADD COLUMN user_id INTEGER NOT NULL DEFAULT 0');
+        }
+
+        if (!isset($cols['note'])) {
+            $this->db->exec('ALTER TABLE prompt_versions ADD COLUMN note TEXT NOT NULL DEFAULT ""');
+        }
+
+        $this->db->exec(
+            'UPDATE prompt_versions
+             SET user_id = 0
+             WHERE user_id IS NULL'
+        );
+    }
+
+    private function tableColumns($table)
+    {
+        $stmt = $this->db->query('PRAGMA table_info(' . $table . ')');
+        $cols = array();
+
+        foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
+            $cols[$row['name']] = true;
+        }
+
+        return $cols;
+    }
+
+    public function supportedLanguages()
+    {
+        return array('en', 'nl');
+    }
+
+    public function languageLabel($language)
+    {
+        if ($language === 'nl') {
+            return 'Nederlands';
+        }
+
+        if ($language === 'en') {
+            return 'English';
+        }
+
+        return $language;
+    }
+
+    /* ------------------------------------------------------------------ */
+    /* Personal prompts                                                    */
+    /* ------------------------------------------------------------------ */
+
+    public function listPrompts($userId, $language = null)
+    {
+        $userId = $this->safeUserId($userId);
+
+        if ($language !== null && $language !== '') {
+            $language = $this->safeLanguage($language);
+
+            $stmt = $this->db->prepare(
+                'SELECT *
+                 FROM prompts
+                 WHERE user_id = :user_id
+                   AND is_default = 0
+                   AND deleted_at IS NULL
+                   AND language = :language
+                 ORDER BY name COLLATE NOCASE'
+            );
+
+            $stmt->execute(array(
+                ':user_id' => $userId,
+                ':language' => $language,
+            ));
+        } else {
+            $stmt = $this->db->prepare(
+                'SELECT *
+                 FROM prompts
+                 WHERE user_id = :user_id
+                   AND is_default = 0
+                   AND deleted_at IS NULL
+                 ORDER BY language, name COLLATE NOCASE'
+            );
+
+            $stmt->execute(array(':user_id' => $userId));
+        }
+
+        return $this->promptRows($stmt);
+    }
+
+    public function getPrompt($userId, $promptId)
+    {
+        $userId = $this->safeUserId($userId);
+        $promptId = $this->safeId($promptId);
+
+        $stmt = $this->db->prepare(
+            'SELECT *
+             FROM prompts
+             WHERE id = :id
+               AND user_id = :user_id
+               AND is_default = 0
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(
+            ':id' => $promptId,
+            ':user_id' => $userId,
+        ));
+
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        return $row ? new PromptRecord($row) : null;
+    }
+
+    public function createPrompt($userId, $name, $language, $content)
+    {
+        $userId = $this->safeUserId($userId);
+        $name = $this->safeName($name);
+        $language = $this->safeLanguage($language);
+        $content = $this->safeContent($content);
+
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO prompts
+             (user_id, is_default, default_key, name, language, content,
+              created_at, updated_at, deleted_at)
+             VALUES
+             (:user_id, 0, NULL, :name, :language, :content,
+              :created_at, :updated_at, NULL)'
+        );
+
+        $stmt->execute(array(
+            ':user_id' => $userId,
+            ':name' => $name,
+            ':language' => $language,
+            ':content' => $content,
+            ':created_at' => $now,
+            ':updated_at' => $now,
+        ));
+
+        $promptId = (int)$this->db->lastInsertId();
+        $this->createVersionForPrompt($promptId, $userId, 'initial version');
+
+        return $this->getPrompt($userId, $promptId);
+    }
+
+    public function updatePrompt($userId, $promptId, $name, $language, $content, $createVersion, $note = '')
+    {
+        $userId = $this->safeUserId($userId);
+        $promptId = $this->safeId($promptId);
+        $name = $this->safeName($name);
+        $language = $this->safeLanguage($language);
+        $content = $this->safeContent($content);
+
+        $prompt = $this->getPrompt($userId, $promptId);
+
+        if ($prompt === null) {
+            throw new PromptStoreException('Prompt not found.');
+        }
+
+        $stmt = $this->db->prepare(
+            'UPDATE prompts
+             SET name = :name,
+                 language = :language,
+                 content = :content,
+                 updated_at = :updated_at
+             WHERE id = :id
+               AND user_id = :user_id
+               AND is_default = 0
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(
+            ':name' => $name,
+            ':language' => $language,
+            ':content' => $content,
+            ':updated_at' => time(),
+            ':id' => $promptId,
+            ':user_id' => $userId,
+        ));
+
+        if ($createVersion) {
+            $this->createVersionForPrompt($promptId, $userId, $note);
+        }
+
+        return $this->getPrompt($userId, $promptId);
+    }
+
+    public function deletePrompt($userId, $promptId)
+    {
+        $userId = $this->safeUserId($userId);
+        $promptId = $this->safeId($promptId);
+
+        $stmt = $this->db->prepare(
+            'UPDATE prompts
+             SET deleted_at = :deleted_at,
+                 updated_at = :updated_at
+             WHERE id = :id
+               AND user_id = :user_id
+               AND is_default = 0
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(
+            ':deleted_at' => time(),
+            ':updated_at' => time(),
+            ':id' => $promptId,
+            ':user_id' => $userId,
+        ));
+    }
+
+    /* ------------------------------------------------------------------ */
+    /* Default prompts                                                     */
+    /* ------------------------------------------------------------------ */
+
+    public function listDefaultPrompts($language = null)
+    {
+        if ($language !== null && $language !== '') {
+            $language = $this->safeLanguage($language);
+
+            $stmt = $this->db->prepare(
+                'SELECT *
+                 FROM prompts
+                 WHERE user_id = 0
+                   AND is_default = 1
+                   AND deleted_at IS NULL
+                   AND language = :language
+                 ORDER BY name COLLATE NOCASE'
+            );
+
+            $stmt->execute(array(':language' => $language));
+        } else {
+            $stmt = $this->db->query(
+                'SELECT *
+                 FROM prompts
+                 WHERE user_id = 0
+                   AND is_default = 1
+                   AND deleted_at IS NULL
+                 ORDER BY language, name COLLATE NOCASE'
+            );
+        }
+
+        return $this->promptRows($stmt);
+    }
+
+    public function getDefaultPrompt($promptId)
+    {
+        $promptId = $this->safeId($promptId);
+
+        $stmt = $this->db->prepare(
+            'SELECT *
+             FROM prompts
+             WHERE id = :id
+               AND user_id = 0
+               AND is_default = 1
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(':id' => $promptId));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        return $row ? new PromptRecord($row) : null;
+    }
+
+    public function createDefaultPrompt($defaultKey, $name, $language, $content)
+    {
+        $defaultKey = $this->safeDefaultKey($defaultKey);
+        $name = $this->safeName($name);
+        $language = $this->safeLanguage($language);
+        $content = $this->safeContent($content);
+
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO prompts
+             (user_id, is_default, default_key, name, language, content,
+              created_at, updated_at, deleted_at)
+             VALUES
+             (0, 1, :default_key, :name, :language, :content,
+              :created_at, :updated_at, NULL)'
+        );
+
+        $stmt->execute(array(
+            ':default_key' => $defaultKey,
+            ':name' => $name,
+            ':language' => $language,
+            ':content' => $content,
+            ':created_at' => $now,
+            ':updated_at' => $now,
+        ));
+
+        $promptId = (int)$this->db->lastInsertId();
+        $this->createVersionForPrompt($promptId, 0, 'initial default version');
+
+        return $this->getDefaultPrompt($promptId);
+    }
+
+    public function updateDefaultPrompt($promptId, $defaultKey, $name, $language, $content, $createVersion, $note = '')
+    {
+        $promptId = $this->safeId($promptId);
+        $defaultKey = $this->safeDefaultKey($defaultKey);
+        $name = $this->safeName($name);
+        $language = $this->safeLanguage($language);
+        $content = $this->safeContent($content);
+
+        $prompt = $this->getDefaultPrompt($promptId);
+
+        if ($prompt === null) {
+            throw new PromptStoreException('Default prompt not found.');
+        }
+
+        $stmt = $this->db->prepare(
+            'UPDATE prompts
+             SET default_key = :default_key,
+                 name = :name,
+                 language = :language,
+                 content = :content,
+                 updated_at = :updated_at
+             WHERE id = :id
+               AND user_id = 0
+               AND is_default = 1
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(
+            ':default_key' => $defaultKey,
+            ':name' => $name,
+            ':language' => $language,
+            ':content' => $content,
+            ':updated_at' => time(),
+            ':id' => $promptId,
+        ));
+
+        if ($createVersion) {
+            $this->createVersionForPrompt($promptId, 0, $note);
+        }
+
+        return $this->getDefaultPrompt($promptId);
+    }
+
+    public function deleteDefaultPrompt($promptId)
+    {
+        $promptId = $this->safeId($promptId);
+
+        $stmt = $this->db->prepare(
+            'UPDATE prompts
+             SET deleted_at = :deleted_at,
+                 updated_at = :updated_at
+             WHERE id = :id
+               AND user_id = 0
+               AND is_default = 1
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(
+            ':deleted_at' => time(),
+            ':updated_at' => time(),
+            ':id' => $promptId,
+        ));
+    }
+
+    public function copyDefaultPromptToUser($userId, $defaultPromptId)
+    {
+        $userId = $this->safeUserId($userId);
+        $defaultPromptId = $this->safeId($defaultPromptId);
+
+        $default = $this->getDefaultPrompt($defaultPromptId);
+
+        if ($default === null) {
+            throw new PromptStoreException('Default prompt not found.');
+        }
+
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO prompts
+             (user_id, is_default, default_key, name, language, content,
+              created_at, updated_at, deleted_at)
+             VALUES
+             (:user_id, 0, :default_key, :name, :language, :content,
+              :created_at, :updated_at, NULL)'
+        );
+
+        $stmt->execute(array(
+            ':user_id' => $userId,
+            ':default_key' => $default->defaultKey(),
+            ':name' => $default->name(),
+            ':language' => $default->language(),
+            ':content' => $default->content(),
+            ':created_at' => $now,
+            ':updated_at' => $now,
+        ));
+
+        $promptId = (int)$this->db->lastInsertId();
+        $this->createVersionForPrompt($promptId, $userId, 'copied from default ' . $default->defaultKey());
+
+        return $this->getPrompt($userId, $promptId);
+    }
+
+    public function copyAllDefaultsToUser($userId, $language)
+    {
+        $userId = $this->safeUserId($userId);
+        $language = $this->safeLanguage($language);
+
+        $defaults = $this->listDefaultPrompts($language);
+        $created = 0;
+
+        foreach ($defaults as $default) {
+            if ($this->userHasPromptForDefault($userId, $default->defaultKey(), $language)) {
+                continue;
+            }
+
+            $this->copyDefaultPromptToUser($userId, $default->id());
+            $created++;
+        }
+
+        return $created;
+    }
+
+    public function userHasPromptForDefault($userId, $defaultKey, $language)
+    {
+        $userId = $this->safeUserId($userId);
+        $defaultKey = $this->safeDefaultKey($defaultKey);
+        $language = $this->safeLanguage($language);
+
+        $stmt = $this->db->prepare(
+            'SELECT id
+             FROM prompts
+             WHERE user_id = :user_id
+               AND is_default = 0
+               AND deleted_at IS NULL
+               AND default_key = :default_key
+               AND language = :language'
+        );
+
+        $stmt->execute(array(
+            ':user_id' => $userId,
+            ':default_key' => $defaultKey,
+            ':language' => $language,
+        ));
+
+        return $stmt->fetch(PDO::FETCH_ASSOC) ? true : false;
+    }
+
+    /* ------------------------------------------------------------------ */
+    /* Versions                                                           */
+    /* ------------------------------------------------------------------ */
+
+    public function createVersion($userId, $promptId, $note = '')
+    {
+        $userId = $this->safeUserId($userId);
+        $promptId = $this->safeId($promptId);
+
+        if ($this->getPrompt($userId, $promptId) === null) {
+            throw new PromptStoreException('Prompt not found.');
+        }
+
+        return $this->createVersionForPrompt($promptId, $userId, $note);
+    }
+
+    public function createDefaultVersion($promptId, $note = '')
+    {
+        $promptId = $this->safeId($promptId);
+
+        if ($this->getDefaultPrompt($promptId) === null) {
+            throw new PromptStoreException('Default prompt not found.');
+        }
+
+        return $this->createVersionForPrompt($promptId, 0, $note);
+    }
+
+    public function listVersions($userId, $promptId)
+    {
+        $userId = $this->safeUserId($userId);
+        $promptId = $this->safeId($promptId);
+
+        if ($this->getPrompt($userId, $promptId) === null) {
+            throw new PromptStoreException('Prompt not found.');
+        }
+
+        return $this->listVersionsForPrompt($promptId);
+    }
+
+    public function listDefaultVersions($promptId)
+    {
+        $promptId = $this->safeId($promptId);
+
+        if ($this->getDefaultPrompt($promptId) === null) {
+            throw new PromptStoreException('Default prompt not found.');
+        }
+
+        return $this->listVersionsForPrompt($promptId);
+    }
+
+    public function restoreVersion($userId, $promptId, $versionNo)
+    {
+        $userId = $this->safeUserId($userId);
+        $promptId = $this->safeId($promptId);
+
+        if ($this->getPrompt($userId, $promptId) === null) {
+            throw new PromptStoreException('Prompt not found.');
+        }
+
+        $this->restoreVersionForPrompt($promptId, $versionNo, $userId);
+    }
+
+    public function restoreDefaultVersion($promptId, $versionNo)
+    {
+        $promptId = $this->safeId($promptId);
+
+        if ($this->getDefaultPrompt($promptId) === null) {
+            throw new PromptStoreException('Default prompt not found.');
+        }
+
+        $this->restoreVersionForPrompt($promptId, $versionNo, 0);
+    }
+
+    private function createVersionForPrompt($promptId, $userId, $note = '')
+    {
+        $promptId = $this->safeId($promptId);
+        $userId = (int)$userId;
+        $note = trim((string)$note);
+
+        if (strlen($note) > 500) {
+            $note = substr($note, 0, 500);
+        }
+
+        $stmt = $this->db->prepare(
+            'SELECT *
+             FROM prompts
+             WHERE id = :id
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(':id' => $promptId));
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            throw new PromptStoreException('Prompt not found.');
+        }
+
+        $stmt = $this->db->prepare(
+            'SELECT COALESCE(MAX(version_no), 0) + 1 AS next_no
+             FROM prompt_versions
+             WHERE prompt_id = :prompt_id'
+        );
+
+        $stmt->execute(array(':prompt_id' => $promptId));
+        $versionRow = $stmt->fetch(PDO::FETCH_ASSOC);
+        $versionNo = (int)$versionRow['next_no'];
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO prompt_versions
+             (prompt_id, user_id, version_no, name, language, content, note, created_at)
+             VALUES
+             (:prompt_id, :user_id, :version_no, :name, :language, :content, :note, :created_at)'
+        );
+
+        $stmt->execute(array(
+            ':prompt_id' => $promptId,
+            ':user_id' => $userId,
+            ':version_no' => $versionNo,
+            ':name' => $row['name'],
+            ':language' => $row['language'],
+            ':content' => $row['content'],
+            ':note' => $note,
+            ':created_at' => time(),
+        ));
+
+        return $versionNo;
+    }
+
+    private function listVersionsForPrompt($promptId)
+    {
+        $promptId = $this->safeId($promptId);
+
+        $stmt = $this->db->prepare(
+            'SELECT *
+             FROM prompt_versions
+             WHERE prompt_id = :prompt_id
+             ORDER BY version_no DESC'
+        );
+
+        $stmt->execute(array(':prompt_id' => $promptId));
+
+        $out = array();
+
+        foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
+            $out[] = new PromptVersionRecord($row);
+        }
+
+        return $out;
+    }
+
+    private function restoreVersionForPrompt($promptId, $versionNo, $userId)
+    {
+        $promptId = $this->safeId($promptId);
+        $versionNo = (int)$versionNo;
+        $userId = (int)$userId;
+
+        if ($versionNo <= 0) {
+            throw new PromptStoreException('Invalid version number.');
+        }
+
+        $stmt = $this->db->prepare(
+            'SELECT *
+             FROM prompt_versions
+             WHERE prompt_id = :prompt_id
+               AND version_no = :version_no'
+        );
+
+        $stmt->execute(array(
+            ':prompt_id' => $promptId,
+            ':version_no' => $versionNo,
+        ));
+
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        if (!$row) {
+            throw new PromptStoreException('Version not found.');
+        }
+
+        $stmt = $this->db->prepare(
+            'UPDATE prompts
+             SET name = :name,
+                 language = :language,
+                 content = :content,
+                 updated_at = :updated_at
+             WHERE id = :id
+               AND deleted_at IS NULL'
+        );
+
+        $stmt->execute(array(
+            ':name' => $row['name'],
+            ':language' => $row['language'],
+            ':content' => $row['content'],
+            ':updated_at' => time(),
+            ':id' => $promptId,
+        ));
+
+        $this->createVersionForPrompt($promptId, $userId, 'restored version ' . $versionNo);
+    }
+
+    /* ------------------------------------------------------------------ */
+    /* Helpers                                                            */
+    /* ------------------------------------------------------------------ */
+
+    private function promptRows($stmt)
+    {
+        $out = array();
+
+        foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
+            $out[] = new PromptRecord($row);
+        }
+
+        return $out;
+    }
+
+    private function safeUserId($userId)
+    {
+        $userId = (int)$userId;
+
+        if ($userId <= 0) {
+            throw new PromptStoreException('Invalid user id.');
+        }
+
+        return $userId;
+    }
+
+    private function safeId($id)
+    {
+        $id = (int)$id;
+
+        if ($id <= 0) {
+            throw new PromptStoreException('Invalid id.');
+        }
+
+        return $id;
+    }
+
+    private function safeName($name)
+    {
+        $name = trim((string)$name);
+
+        if ($name === '') {
+            throw new PromptStoreException('Prompt name is required.');
+        }
+
+        if (strlen($name) > 160) {
+            throw new PromptStoreException('Prompt name is too long.');
+        }
+
+        return $name;
+    }
+
+    private function safeLanguage($language)
+    {
+        $language = strtolower(trim((string)$language));
+
+        if (!in_array($language, $this->supportedLanguages(), true)) {
+            throw new PromptStoreException('Unsupported language: ' . $language);
+        }
+
+        return $language;
+    }
+
+    private function safeContent($content)
+    {
+        $content = trim((string)$content);
+
+        if ($content === '') {
+            throw new PromptStoreException('Prompt content is required.');
+        }
+
+        if (strlen($content) > 200000) {
+            throw new PromptStoreException('Prompt content is too large.');
+        }
+
+        return $content;
+    }
+
+    private function safeDefaultKey($key)
+    {
+        $key = trim((string)$key);
+
+        if ($key === '') {
+            throw new PromptStoreException('Default key is required.');
+        }
+
+        if (!preg_match('/^[A-Za-z0-9_-]+$/', $key)) {
+            throw new PromptStoreException('Invalid default key.');
+        }
+
+        return $key;
+    }
+
+public function deleteVersion($userId, $promptId, $versionNo)
+{
+    $userId = $this->safeUserId($userId);
+    $promptId = $this->safeId($promptId);
+    $versionNo = (int)$versionNo;
+
+    if ($versionNo <= 0) {
+        throw new PromptStoreException('Invalid version number.');
+    }
+
+    if ($this->getPrompt($userId, $promptId) === null) {
+        throw new PromptStoreException('Prompt not found.');
+    }
+
+    $this->deleteVersionForPrompt($promptId, $versionNo);
+}
+
+public function deleteDefaultVersion($promptId, $versionNo)
+{
+    $promptId = $this->safeId($promptId);
+    $versionNo = (int)$versionNo;
+
+    if ($versionNo <= 0) {
+        throw new PromptStoreException('Invalid version number.');
+    }
+
+    if ($this->getDefaultPrompt($promptId) === null) {
+        throw new PromptStoreException('Default prompt not found.');
+    }
+
+    $this->deleteVersionForPrompt($promptId, $versionNo);
+}
+
+private function deleteVersionForPrompt($promptId, $versionNo)
+{
+    $promptId = $this->safeId($promptId);
+    $versionNo = (int)$versionNo;
+
+    $stmt = $this->db->prepare(
+        'SELECT COUNT(*) AS n
+         FROM prompt_versions
+         WHERE prompt_id = :prompt_id'
+    );
+
+    $stmt->execute(array(':prompt_id' => $promptId));
+    $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+    if (!$row || (int)$row['n'] <= 1) {
+        throw new PromptStoreException('Cannot delete the last remaining version.');
+    }
+
+    $stmt = $this->db->prepare(
+        'DELETE FROM prompt_versions
+         WHERE prompt_id = :prompt_id
+           AND version_no = :version_no'
+    );
+
+    $stmt->execute(array(
+        ':prompt_id' => $promptId,
+        ':version_no' => $versionNo,
+    ));
+
+    if ($stmt->rowCount() !== 1) {
+        throw new PromptStoreException('Version not found.');
+    }
+}    
+}
\ No newline at end of file
diff --git a/racketzip.php b/racketzip.php
new file mode 100644
index 0000000..20890c8
--- /dev/null
+++ b/racketzip.php
@@ -0,0 +1,196 @@
+<?php
+/*
+ * Shared handling for the Racket installation zip and its binary parts.
+ */
+
+define('RACKET_ZIP_FILE', __DIR__ . '/config/racket.zip');
+define('RACKET_ZIP_DATA_DIR', __DIR__ . '/data');
+define('RACKET_ZIP_PART_PREFIX', 'racket-part-');
+define('RACKET_ZIP_MANIFEST_FILE', RACKET_ZIP_DATA_DIR . '/racket-parts.json');
+
+function racket_zip_binary_chunk_bytes_for_base64_kib($kib)
+{
+    return intdiv(((int)$kib) * 1024, 4) * 3;
+}
+
+function racket_zip_part_name($nr)
+{
+    return RACKET_ZIP_PART_PREFIX . sprintf('%06d', $nr);
+}
+
+function racket_zip_part_file($partNumber)
+{
+    return RACKET_ZIP_DATA_DIR . '/' . RACKET_ZIP_PART_PREFIX . $partNumber;
+}
+
+function racket_zip_ensure_data_dir()
+{
+    if (!is_dir(RACKET_ZIP_DATA_DIR)) {
+        if (!mkdir(RACKET_ZIP_DATA_DIR, 0755, true)) {
+            throw new RuntimeException('Kan data directory niet maken: ' . RACKET_ZIP_DATA_DIR);
+        }
+    }
+
+    if (!is_writable(RACKET_ZIP_DATA_DIR)) {
+        throw new RuntimeException('Data directory is niet schrijfbaar: ' . RACKET_ZIP_DATA_DIR);
+    }
+}
+
+function racket_zip_remove_old_parts()
+{
+    foreach (glob(RACKET_ZIP_DATA_DIR . '/' . RACKET_ZIP_PART_PREFIX . '*') ?: array() as $file) {
+        if (is_file($file)) {
+            @unlink($file);
+        }
+    }
+
+    if (is_file(RACKET_ZIP_MANIFEST_FILE)) {
+        @unlink(RACKET_ZIP_MANIFEST_FILE);
+    }
+}
+
+function split_racket_zip_parts($maxBase64Kib)
+{
+    $maxBase64Bytes = (int)$maxBase64Kib * 1024;
+    $binaryChunkBytes = racket_zip_binary_chunk_bytes_for_base64_kib($maxBase64Kib);
+
+    if ($binaryChunkBytes < 3) {
+        throw new RuntimeException('Ongeldige racket.zip base64 chunk-instelling.');
+    }
+
+    if (!is_file(RACKET_ZIP_FILE) || !is_readable(RACKET_ZIP_FILE)) {
+        throw new RuntimeException('racket.zip ontbreekt of is niet leesbaar: ' . RACKET_ZIP_FILE);
+    }
+
+    racket_zip_ensure_data_dir();
+    racket_zip_remove_old_parts();
+
+    $in = fopen(RACKET_ZIP_FILE, 'rb');
+
+    if ($in === false) {
+        throw new RuntimeException('Kan racket.zip niet openen.');
+    }
+
+    $parts = array();
+    $nr = 1;
+    $totalBinaryBytes = 0;
+
+    while (!feof($in)) {
+        $buf = fread($in, $binaryChunkBytes);
+
+        if ($buf === false) {
+            fclose($in);
+            throw new RuntimeException('Fout bij lezen van racket.zip.');
+        }
+
+        if ($buf === '') {
+            break;
+        }
+
+        $name = racket_zip_part_name($nr);
+        $file = RACKET_ZIP_DATA_DIR . '/' . $name;
+
+        if (file_put_contents($file, $buf, LOCK_EX) === false) {
+            fclose($in);
+            throw new RuntimeException('Kan part niet schrijven: ' . $file);
+        }
+
+        $n = sprintf('%06d', $nr);
+        $binaryBytes = strlen($buf);
+
+        $parts[] = array(
+            'number' => $n,
+            'name' => $name,
+            'file' => $file,
+            'size' => $binaryBytes,
+        );
+
+        $totalBinaryBytes += $binaryBytes;
+        $nr++;
+    }
+
+    fclose($in);
+
+    if (count($parts) === 0) {
+        throw new RuntimeException('racket.zip lijkt leeg te zijn.');
+    }
+
+    $manifest = array(
+        'source_file' => RACKET_ZIP_FILE,
+        'source_bytes' => filesize(RACKET_ZIP_FILE),
+        'source_mtime' => filemtime(RACKET_ZIP_FILE),
+        'source_sha256' => hash_file('sha256', RACKET_ZIP_FILE),
+        'max_base64_kib' => (int)$maxBase64Kib,
+        'max_base64_bytes' => $maxBase64Bytes,
+        'binary_chunk_bytes' => $binaryChunkBytes,
+        'part_count' => count($parts),
+        'total_binary_bytes' => $totalBinaryBytes,
+        'parts' => $parts,
+        'created_at' => gmdate('c'),
+    );
+
+    if (file_put_contents(
+        RACKET_ZIP_MANIFEST_FILE,
+        json_encode($manifest, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . "\n",
+        LOCK_EX
+    ) === false) {
+        throw new RuntimeException('Kan racket.zip manifest niet schrijven: ' . RACKET_ZIP_MANIFEST_FILE);
+    }
+
+    return $manifest;
+}
+
+function load_racket_zip_parts_manifest()
+{
+    if (!is_file(RACKET_ZIP_MANIFEST_FILE) || !is_readable(RACKET_ZIP_MANIFEST_FILE)) {
+        throw new RuntimeException('racket.zip parts-manifest ontbreekt: ' . RACKET_ZIP_MANIFEST_FILE);
+    }
+
+    $raw = file_get_contents(RACKET_ZIP_MANIFEST_FILE);
+
+    if ($raw === false) {
+        throw new RuntimeException('Kan racket.zip parts-manifest niet lezen: ' . RACKET_ZIP_MANIFEST_FILE);
+    }
+
+    $manifest = json_decode($raw, true);
+
+    if (!is_array($manifest)) {
+        throw new RuntimeException('racket.zip parts-manifest is geen geldige JSON: ' . RACKET_ZIP_MANIFEST_FILE);
+    }
+
+    return $manifest;
+}
+
+function racket_zip_parts_current($manifest, $maxBase64Kib)
+{
+    if (!is_array($manifest)) {
+        return false;
+    }
+
+    if ((int)($manifest['max_base64_kib'] ?? 0) !== (int)$maxBase64Kib) {
+        return false;
+    }
+
+    if (!is_file(RACKET_ZIP_FILE)) {
+        return false;
+    }
+
+    if ((int)($manifest['source_bytes'] ?? -1) !== (int)filesize(RACKET_ZIP_FILE)) {
+        return false;
+    }
+
+    if ((int)($manifest['source_mtime'] ?? -1) !== (int)filemtime(RACKET_ZIP_FILE)) {
+        return false;
+    }
+
+    foreach (($manifest['parts'] ?? array()) as $part) {
+        $number = (string)($part['number'] ?? '');
+        $file = racket_zip_part_file($number);
+
+        if (!preg_match('/^[0-9]{6}$/', $number) || !is_file($file) || !is_readable($file)) {
+            return false;
+        }
+    }
+
+    return count($manifest['parts'] ?? array()) > 0;
+}
diff --git a/rkt.php b/rkt.php
new file mode 100644
index 0000000..a7c72c6
--- /dev/null
+++ b/rkt.php
@@ -0,0 +1,312 @@
+<?php
+/*
+ * Simpele Racket bootstrap.
+ *
+ * .htaccess:
+ *
+ *   FallbackResource /index.php
+ *
+ * Bestanden:
+ *
+ *   config/racket.zip
+ *   data/          bevat vooraf gemaakte parts
+ *
+ * Routes:
+ *
+ *   /bootstrap-racket?next=...
+ *      Leest de vooraf gemaakte parts in data/ en toont een HTML-index
+ *      met links.
+ *
+ *   /bootstrap-racket-part?n=000001&next=...
+ *      Geeft text/plain met base64 van precies één binair part.
+ *
+ * Regels:
+ *
+ *   - Indexen/lijsten zijn HTML.
+ *   - Payload/downloads zijn text/plain.
+ *   - Payload/downloads zijn altijd base64.
+ *   - Geen .bin, .zip of bestandsnaam in download-URL’s.
+ *   - next=... is alleen cache-busting.
+ *   - Per gegenereerde HTML-pagina wordt één next-id gemaakt en voor alle
+ *     links op die pagina gebruikt.
+ */
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+require_once __DIR__ . '/nexttoken.php';
+require_once __DIR__ . '/base64config.php';
+require_once __DIR__ . '/racketzip.php';
+
+$TOKENS = new NextTokenStore(__DIR__ . '/data/racket-sandbox.sqlite');
+
+@set_time_limit(300);
+ignore_user_abort(false);
+
+$chunkConfig = load_base64_chunk_config();
+$racketZipMaxBase64Kb = (int)($chunkConfig['racket_zip_max_base64_kb'] ?? 8192);
+
+if ($racketZipMaxBase64Kb < 1) {
+    $racketZipMaxBase64Kb = 1;
+}
+
+define('RACKET_ZIP_MAX_BASE64_KB', $racketZipMaxBase64Kb);
+define('RACKET_ZIP_MAX_BASE64_BYTES', RACKET_ZIP_MAX_BASE64_KB * 1024);
+define('RACKET_ZIP_BINARY_CHUNK_BYTES', racket_zip_binary_chunk_bytes_for_base64_kib(RACKET_ZIP_MAX_BASE64_KB));
+
+if (RACKET_ZIP_BINARY_CHUNK_BYTES < 3) {
+    fail_html('Ongeldige racket.zip base64 chunk-instelling.');
+}
+
+/*
+ * Eén next-id voor alle URLs die deze request genereert.
+ */
+$NEXT_ID = $TOKENS->create();
+
+function path_only()
+{
+    $p = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH);
+    $p = '/' . trim($p ?: '/', '/');
+    return $p === '/' ? '/' : $p;
+}
+
+function scheme()
+{
+    if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
+        return strtolower(trim(explode(',', $_SERVER['HTTP_X_FORWARDED_PROTO'])[0]));
+    }
+
+    return (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https' : 'http';
+}
+
+function host_name()
+{
+    return $_SERVER['HTTP_HOST'] ?? 'localhost';
+}
+
+function make_url($path, $query = array())
+{
+    global $NEXT_ID;
+
+    $query['next'] = $NEXT_ID;
+
+    return scheme() . '://' . host_name() . $path . '?' . http_build_query($query);
+}
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function html_response($html, $status = 200)
+{
+    http_response_code($status);
+    header('Content-Type: text/html; charset=utf-8');
+    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
+    header('Pragma: no-cache');
+    echo $html;
+    exit;
+}
+
+function text_response($text, $status = 200)
+{
+    http_response_code($status);
+    header('Content-Type: text/plain; charset=us-ascii');
+    header('Content-Disposition: inline');
+    header('X-Content-Type-Options: nosniff');
+    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
+    header('Pragma: no-cache');
+
+    echo $text;
+
+    if ($text === '' || substr($text, -1) !== "\n") {
+        echo "\n";
+    }
+
+    exit;
+}
+
+function fail_html($message, $status = 500)
+{
+    html_response(
+        '<!doctype html>' .
+        '<html><head><meta charset="utf-8"><title>Error</title></head>' .
+        '<body><h1>Error</h1><pre>' . h($message) . '</pre></body></html>',
+        $status
+    );
+}
+
+function fail_text($message, $status = 500)
+{
+    text_response("error: " . $message . "\n", $status);
+}
+
+function load_parts()
+{
+    try {
+        $manifest = load_racket_zip_parts_manifest();
+    } catch (Throwable $e) {
+        fail_html($e->getMessage() . "\n\nSla de configuratiepagina op om racket.zip in parts te verdelen.");
+    }
+
+    if (!racket_zip_parts_current($manifest, RACKET_ZIP_MAX_BASE64_KB)) {
+        fail_html(
+            "racket.zip parts ontbreken of passen niet bij de huidige chunk-grootte.\n\n" .
+            "Sla de configuratiepagina op om de parts opnieuw te maken."
+        );
+    }
+
+    $parts = array();
+
+    foreach (($manifest['parts'] ?? array()) as $part) {
+        $number = (string)($part['number'] ?? '');
+        $parts[] = array(
+            'number' => $number,
+            'name' => (string)($part['name'] ?? racket_zip_part_name((int)$number)),
+            'size' => (int)($part['size'] ?? 0),
+            'url' => make_url('/bootstrap-racket-part', array('n' => $number)),
+        );
+    }
+
+    $manifest['parts'] = $parts;
+
+    return $manifest;
+}
+
+function serve_bootstrap()
+{
+    global $NEXT_ID;
+
+    $manifest = load_parts();
+    $parts = $manifest['parts'];
+
+    $rows = '';
+
+    foreach ($parts as $i => $part) {
+        $rows .=
+            '<tr>' .
+            '<td>' . h((string)($i + 1)) . '</td>' .
+            '<td>' . h($part['number']) . '</td>' .
+            '<td>' . h((string)$part['size']) . '</td>' .
+            '<td><a href="' . h($part['url']) . '">' . h($part['url']) . '</a></td>' .
+            '</tr>' . "\n";
+    }
+
+    $zipSize = (int)($manifest['source_bytes'] ?? 0);
+
+    $pkg_url = make_url('/racket-pkg-index');
+
+    html_response('<!doctype html>
+<html lang="nl">
+<head>
+<meta charset="utf-8">
+<title>Racket bootstrap</title>
+<link rel="stylesheet" href="/styles.css">
+</head>
+<body class="simple-doc">
+
+<h1>Racket bootstrap</h1>
+
+<p>
+<code>racket.zip</code> is vooraf via de configuratiepagina gesplitst naar
+parts in de map <code>data</code>.
+</p>
+
+<p>
+Package index: <a href="' .  $pkg_url . '"> Racket package index</a>
+</p>
+
+<p>
+Bronbestand: <code>config/racket.zip</code><br>
+Bronbestand bytes: <code>' . h((string)$zipSize) . '</code><br>
+Maximale base64 part-grootte: <code>' . h((string)RACKET_ZIP_MAX_BASE64_KB) . '</code> KiB (<code>' . h((string)RACKET_ZIP_MAX_BASE64_BYTES) . '</code> bytes)<br>
+Binaire chunk-grootte: <code>' . h((string)RACKET_ZIP_BINARY_CHUNK_BYTES) . '</code> bytes<br>
+Aantal parts: <code>' . h((string)count($parts)) . '</code><br>
+Parts gemaakt op: <code>' . h((string)($manifest['created_at'] ?? '')) . '</code><br>
+next-id voor alle links op deze pagina: <code>' . h($NEXT_ID) . '</code>
+</p>
+
+<p>
+Elke link hieronder geeft <strong>text/plain</strong> met de
+<strong>base64-representatie van één binair part</strong>.
+De URL bevat alleen een nummer, geen bestandsnaam en geen extensie.
+</p>
+
+<table>
+<thead>
+<tr>
+<th>#</th>
+<th>partnummer</th>
+<th>bytes</th>
+<th>base64 text/plain URL</th>
+</tr>
+</thead>
+<tbody>
+' . $rows . '
+</tbody>
+</table>
+
+<h2>Reconstructie in de sandbox</h2>
+
+<p>
+Decodeer ieder base64-part afzonderlijk naar een binair part. Plak daarna de
+binaire parts in numerieke volgorde aan elkaar.
+</p>
+
+<pre>
+base64 -d part-000001.txt &gt; part-000001
+base64 -d part-000002.txt &gt; part-000002
+base64 -d part-000003.txt &gt; part-000003
+# enzovoort
+
+cat part-* &gt; racket.zip
+unzip racket.zip -d /tmp/racket
+</pre>
+
+</body>
+</html>');
+}
+
+function serve_part()
+{
+    $n = $_GET['n'] ?? '';
+
+    if (!is_string($n) || !preg_match('/^[0-9]{6}$/', $n)) {
+        fail_text('ongeldig partnummer; gebruik bijvoorbeeld n=000001', 400);
+    }
+
+    $file = racket_zip_part_file($n);
+
+    if (!is_file($file) || !is_readable($file)) {
+        fail_text('part ontbreekt of is niet leesbaar: ' . $n, 404);
+    }
+
+    $bin = file_get_contents($file);
+
+    if ($bin === false) {
+        fail_text('kan part niet lezen: ' . $n, 500);
+    }
+
+    text_response(base64_encode($bin));
+}
+
+$path = path_only();
+
+if ($path === '/' || $path === '/index.php') {
+    header('Location: ' . make_url('/bootstrap-racket'), true, 302);
+    exit;
+}
+
+if ($path === '/bootstrap-racket') {
+    $TOKENS->check_valid_next('html');
+    serve_bootstrap();
+}
+
+if ($path === '/bootstrap-racket-part') {
+    $TOKENS->check_valid_next('text');
+    serve_part();
+}
+
+fail_html('Onbekende route: ' . $path, 404);
diff --git a/rktpkgs.php b/rktpkgs.php
new file mode 100644
index 0000000..bb2ebb3
--- /dev/null
+++ b/rktpkgs.php
@@ -0,0 +1,187 @@
+<?php
+/*
+ * rktpkgs.php
+ *
+ * Maakt een volledige HTML-index van de Racket package catalogus.
+ *
+ * Bron:
+ *   https://pkgs.racket-lang.org/pkgs-all
+ *
+ * Output:
+ *   Alleen HTML.
+ *
+ * Package-links:
+ *   /package?name=<pkg-name>&next=<id>
+ *
+ * Regels:
+ *   - Geen filterveld.
+ *   - Geen git-adressen tonen.
+ *   - Geen package-details tonen.
+ *   - Geen package-downloads implementeren in dit script.
+ *   - De package-naam zelf is de link.
+ *   - Eén next-id per gegenereerde HTML-pagina.
+ *
+ * .htaccess:
+ *
+ *   Options -MultiViews
+ *   RewriteEngine On
+ *   RewriteRule ^racket-pkg-index$ rktpkgs.php [L,QSA]
+ */
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+require_once __DIR__ . '/nexttoken.php';
+require_once __DIR__ . '/lib/catalog-http.php';
+require_once __DIR__ . '/lib/racket-data.php';
+
+$TOKENS = new NextTokenStore(__DIR__ . '/data/racket-sandbox.sqlite');
+
+@set_time_limit(180);
+ignore_user_abort(false);
+
+define('CATALOG_PKGS_ALL', 'https://pkgs.racket-lang.org/pkgs-all');
+
+define('CACHE_DIR', __DIR__ . '/data');
+define('CACHE_FILE', CACHE_DIR . '/pkgs-all.rktd');
+define('CACHE_META_FILE', CACHE_DIR . '/pkgs-all.meta.json');
+define('CACHE_TTL', 3600);
+
+/*
+ * Eén next-id voor alle package-links op deze pagina.
+ */
+$NEXT_ID = $TOKENS->create();
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function current_scheme()
+{
+    if (!empty($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
+        return strtolower(trim(explode(',', $_SERVER['HTTP_X_FORWARDED_PROTO'])[0]));
+    }
+
+    return (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https' : 'http';
+}
+
+function current_host()
+{
+    return $_SERVER['HTTP_HOST'] ?? 'localhost';
+}
+
+function make_url($path, $query = array())
+{
+    global $NEXT_ID;
+
+    $query['next'] = $NEXT_ID;
+
+    return current_scheme() . '://' . current_host() . $path . '?' . http_build_query($query);
+}
+
+function html_response($html, $status = 200)
+{
+    http_response_code($status);
+    header('Content-Type: text/html; charset=utf-8');
+    header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
+    header('Pragma: no-cache');
+
+    echo $html;
+    exit;
+}
+
+function fail_html($message, $status = 500)
+{
+    html_response(
+        '<!doctype html>' .
+        '<html><head><meta charset="utf-8"><title>Error</title></head>' .
+        '<body><h1>Error</h1><pre>' . h($message) . '</pre></body></html>',
+        $status
+    );
+}
+
+function get_pkgs_all_text()
+{
+    try {
+        return catalog_http_fetch_cached(
+            CATALOG_PKGS_ALL,
+            CACHE_FILE,
+            CACHE_META_FILE,
+            CACHE_TTL,
+            'rktsndbx-rktpkgs/1.0',
+            180
+        );
+    } catch (Throwable $e) {
+        fail_html($e->getMessage());
+    }
+}
+
+function serve_index()
+{
+    global $NEXT_ID;
+
+    $text = get_pkgs_all_text();
+    $names = rktd_extract_top_level_package_names($text);
+
+    if (count($names) === 0) {
+        fail_html('Geen package-namen gevonden in pkgs-all.');
+    }
+
+    $rows = '';
+
+    foreach ($names as $i => $name) {
+        $url = make_url('/package', array('name' => $name));
+
+        $rows .=
+            '<tr id="pkg-' . h($name) . '">' .
+            '<td>' . h((string)($i + 1)) . '</td>' .
+            '<td class="pkg-name">' .
+            '<a class="pkg-link" href="' . h($url) . '">' . h($name) . '</a>' .
+            '</td>' .
+            '</tr>' . "\n";
+    }
+
+    html_response('<!doctype html>
+<html lang="nl">
+<head>
+<meta charset="utf-8">
+<title>Racket package index</title>
+<link rel="stylesheet" href="/styles.css">
+</head>
+<body class="simple-doc package-index-page">
+
+<h1>Racket package index</h1>
+
+<p>
+Volledige HTML-index van de Racket package catalogus op basis van
+<code>pkgs-all</code>. De package-naam is de ophaallink via
+<code>rktsndbx.dijkewijk.nl</code>.
+</p>
+
+<p>
+Aantal packages: <code>' . h((string)count($names)) . '</code><br>
+next-id voor alle package-links op deze pagina:
+<code>' . h($NEXT_ID) . '</code>
+</p>
+
+<table>
+<thead>
+<tr>
+<th>#</th>
+<th>package</th>
+</tr>
+</thead>
+<tbody>
+' . $rows . '
+</tbody>
+</table>
+
+</body>
+</html>');
+}
+
+$TOKENS->check_valid_next('html');
+serve_index();
diff --git a/styles.css b/styles.css
new file mode 100644
index 0000000..2cb3fe5
--- /dev/null
+++ b/styles.css
@@ -0,0 +1,932 @@
+html,
+body {
+    height: 100%;
+    margin: 0;
+}
+
+body {
+    font-family: Verdana, Arial, sans-serif;
+    font-size: 14px;
+    line-height: 1.45;
+    overflow: hidden;
+    color: #242424;
+    background: #e7e7e7;
+}
+
+body.simple-doc {
+    height: auto;
+    min-height: 100%;
+    overflow: auto;
+    margin: 2rem;
+    background: #fff;
+}
+
+body.simple-doc table {
+    margin: 0.75rem 0 1.5rem 0;
+}
+
+body.simple-doc pre {
+    background: #f5f5f5;
+    padding: 8px;
+    overflow: auto;
+}
+
+body.login-page form {
+    max-width: 28rem;
+}
+
+body.login-page .login-layout {
+    display: flex;
+    align-items: flex-start;
+    gap: 2rem;
+    max-width: 58rem;
+}
+
+body.login-page .login-panel {
+    flex: 1 1 28rem;
+}
+
+body.login-page .login-request-panel {
+    flex: 0 1 22rem;
+    border-left: 1px solid #ddd;
+    padding-left: 1.5rem;
+}
+
+body.login-page .login-request-panel h2 {
+    margin-top: 0.35rem;
+}
+
+body.login-page label {
+    display: block;
+    margin: 0.7rem 0;
+}
+
+body.login-page input[type=email],
+body.login-page input[type=password] {
+    width: 100%;
+    box-sizing: border-box;
+}
+
+body.login-page button {
+    margin-top: 0.7rem;
+}
+
+@media (max-width: 720px) {
+    body.login-page .login-layout {
+        flex-direction: column;
+        gap: 1rem;
+    }
+
+    body.login-page .login-request-panel {
+        border-left: none;
+        border-top: 1px solid #ddd;
+        padding-left: 0;
+        padding-top: 1rem;
+    }
+}
+
+.pkg-name,
+.pkg-link {
+    font-family: Consolas, "Courier New", monospace;
+    white-space: nowrap;
+}
+
+.page {
+    height: 100vh;
+    display: grid;
+    grid-template-rows: auto 1fr auto;
+    padding: 1rem;
+    box-sizing: border-box;
+    gap: 0.6rem;
+}
+
+.page-header {
+    min-height: 0;
+}
+
+.page-titlebar {
+    display: grid;
+    grid-template-columns: auto 1fr;
+    align-items: center;
+    gap: 1rem;
+    padding: 0.7rem 0.85rem;
+    border: 1px solid #c8c8c8;
+    background: #f4f4f4;
+    box-shadow: 0 1px 0 rgba(255, 255, 255, 0.8) inset;
+}
+
+.page-titlebar h1 {
+    margin: 0;
+    white-space: nowrap;
+    color: #303030;
+    font-size: 1.45rem;
+}
+
+.header-nav {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    justify-content: flex-end;
+    gap: 0.35rem 0.45rem;
+    min-width: 0;
+}
+
+.header-nav a,
+.header-nav strong,
+.nav-user {
+    white-space: nowrap;
+}
+
+.nav-separator {
+    color: #8a8a8a;
+    line-height: 1;
+}
+
+.header-nav a,
+.header-nav strong {
+    display: inline-block;
+    padding: 0.32rem 0.65rem;
+    border: 1px solid #aaa;
+    border-radius: 4px;
+    background: #ededed;
+    color: #252525;
+    text-decoration: none;
+    line-height: 1.2;
+}
+
+.header-nav a:hover,
+.header-nav a:focus {
+    background: #dedede;
+    border-color: #888;
+}
+
+.header-nav strong {
+    background: #555;
+    border-color: #555;
+    color: #fff;
+}
+
+.nav-user {
+    color: #454545;
+}
+
+.header-language-form {
+    margin: 0;
+}
+
+.header-action-form {
+    margin: 0;
+}
+
+.header-action-form button {
+    margin: 0;
+}
+
+.header-language-form label {
+    display: flex;
+    align-items: center;
+    gap: 0.35rem;
+    white-space: nowrap;
+}
+
+.header-language-form select {
+    padding: 0.25rem 0.4rem;
+    border: 1px solid #aaa;
+    border-radius: 4px;
+    background: #fff;
+}
+
+.page-main {
+    min-height: 0;
+    overflow: auto;
+    display: grid;
+    gap: 0.8rem;
+}
+
+.page-footer {
+    border-top: 1px solid #ddd;
+    padding-top: 0.4rem;
+}
+
+fieldset {
+    border: 1px solid #ccc;
+    padding: 0.8rem;
+    margin: 0.75rem 0 0 0;
+}
+
+legend {
+    font-weight: bold;
+}
+
+label {
+    display: block;
+    margin: 0.35rem 0;
+}
+
+input[type=password],
+input[type=number] {
+    width: 28rem;
+    max-width: 100%;
+    box-sizing: border-box;
+}
+
+.copy-box {
+    width: 100%;
+    box-sizing: border-box;
+}
+
+.generated-link-row {
+    display: inline-flex;
+    max-width: 100%;
+    align-items: center;
+    gap: 0.55rem;
+}
+
+.bootstrap-result-grid {
+    display: grid;
+    grid-template-columns: minmax(18rem, 0.9fr) minmax(22rem, 1.1fr);
+    gap: 1rem;
+    align-items: start;
+}
+
+.generated-link-row a {
+    max-width: min(72vw, 70rem);
+    overflow-wrap: anywhere;
+    padding: 0.45rem 0.55rem;
+    border: 1px solid #ccc;
+    background: #fff;
+}
+
+.bootstrap-prompt-tool {
+    display: grid;
+    gap: 0.55rem;
+    max-width: min(76vw, 72rem);
+}
+
+.bootstrap-prompt-tool select,
+.bootstrap-prompt-tool textarea {
+    width: 100%;
+    box-sizing: border-box;
+}
+
+.bootstrap-prompt-tool textarea {
+    min-height: 14rem;
+    resize: vertical;
+}
+
+@media (max-width: 720px) {
+    .bootstrap-result-grid {
+        grid-template-columns: 1fr;
+    }
+}
+
+.admin-form-grid,
+.user-row-form {
+    display: grid;
+    grid-template-columns: minmax(11rem, 1.2fr) minmax(14rem, 1.4fr) auto auto auto;
+    align-items: end;
+    gap: 0.55rem;
+}
+
+.admin-form-grid input[type=text],
+.admin-form-grid input[type=email],
+.admin-form-grid input[type=password],
+.admin-form-grid input[type=number],
+.user-row-form input[type=text],
+.user-row-form input[type=email],
+.user-row-actions input[type=password] {
+    width: 100%;
+    box-sizing: border-box;
+}
+
+.user-row-actions {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: end;
+    gap: 0.7rem;
+    margin-top: 0.55rem;
+    padding-top: 0.55rem;
+    border-top: 1px solid #ddd;
+}
+
+.user-row-actions form {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: end;
+    gap: 0.45rem;
+}
+
+.panel {
+    border: 1px solid #c8c8c8;
+    padding: 0.75rem;
+    background: #f8f8f8;
+}
+
+h1,
+h2,
+h3 {
+    margin: 0.4rem 0 0.6rem 0;
+}
+
+p {
+    margin: 0.4rem 0;
+}
+
+table {
+    border-collapse: collapse;
+    width: 100%;
+    margin: 0.5rem 0;
+}
+
+th,
+td {
+    border: 1px solid #ccc;
+    padding: 4px 6px;
+    vertical-align: top;
+}
+
+th {
+    text-align: left;
+    background: #ececec;
+}
+
+.token-valid td {
+    background: #edf8ed;
+    color: #176127;
+}
+
+.token-expired td {
+    background: #fff0f0;
+    color: #9d1c1c;
+}
+
+code,
+pre,
+textarea {
+    font-family: Consolas, "Courier New", monospace;
+}
+
+textarea {
+    width: 100%;
+    box-sizing: border-box;
+}
+
+input[type=text],
+select {
+    max-width: 100%;
+}
+
+button {
+    margin: 0.15rem 0.15rem 0.15rem 0;
+    padding: 0.32rem 0.65rem;
+    border: 1px solid #999;
+    border-radius: 4px;
+    background: #e9e9e9;
+    color: #242424;
+    cursor: pointer;
+}
+
+button:hover,
+button:focus {
+    background: #dcdcdc;
+    border-color: #777;
+}
+
+.message {
+    padding: 0.5rem;
+    background: #eef8ee;
+    border: 1px solid #9c9;
+    margin: 0.5rem 0;
+}
+
+.error {
+    padding: 0.5rem;
+    background: #fff0f0;
+    border: 1px solid #c99;
+    margin: 0.5rem 0;
+}
+
+.small {
+    color: #555;
+    font-size: 12px;
+}
+
+.actions form,
+.version-actions form {
+    display: inline;
+}
+
+.language-label {
+    font-weight: bold;
+    margin-right: 0.45rem;
+}
+
+.language-switch a,
+.language-switch .active-language {
+    display: inline-block;
+    margin: 0.15rem 0.35rem 0.15rem 0;
+    padding: 0.24rem 0.55rem;
+    border: 1px solid #aaa;
+    border-radius: 4px;
+    background: #ededed;
+    color: #252525;
+    text-decoration: none;
+}
+
+.language-switch .active-language {
+    background: #555;
+    border-color: #555;
+    color: #fff;
+}
+
+.hidden {
+    display: none;
+}
+
+/* Prompt workbench */
+
+.prompt-workbench {
+    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
+    overflow: hidden;
+    align-items: stretch;
+}
+
+.prompt-sidebar,
+.prompt-viewer {
+    min-height: 0;
+    overflow: hidden;
+}
+
+.prompt-sidebar {
+    display: flex;
+    flex-direction: column;
+    gap: 0.7rem;
+}
+
+.prompt-tabs {
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: 0.35rem;
+}
+
+.prompt-tab {
+    width: 100%;
+    min-height: 2.5rem;
+    margin: 0;
+}
+
+.prompt-tab.active {
+    background: #555;
+    border-color: #555;
+    color: #fff;
+}
+
+.prompt-tab[data-tab="defaults"].active {
+    border-color: #8a6a1f;
+}
+
+.prompt-tab-panel {
+    flex: 1;
+    min-height: 0;
+    display: none;
+    flex-direction: column;
+    gap: 0.55rem;
+    overflow: hidden;
+}
+
+.prompt-tab-panel.active {
+    display: flex;
+}
+
+.sidebar-actions {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.35rem;
+}
+
+.sidebar-actions button {
+    margin: 0;
+}
+
+.default-admin-notice {
+    display: grid;
+    gap: 0.15rem;
+    padding: 0.55rem 0.65rem;
+    border: 1px solid #c7a949;
+    border-left: 4px solid #8a6a1f;
+    background: #fff8dc;
+    color: #3d3214;
+}
+
+.default-admin-notice strong {
+    font-size: 13px;
+}
+
+.default-admin-notice span {
+    font-size: 12px;
+}
+
+.prompt-list {
+    flex: 1;
+    min-height: 0;
+    overflow: auto;
+    display: grid;
+    align-content: start;
+    gap: 0.45rem;
+    padding-right: 0.15rem;
+}
+
+.prompt-list-item {
+    display: grid;
+    grid-template-columns: minmax(0, 1fr) auto auto;
+    align-items: center;
+    gap: 0.35rem;
+}
+
+.prompt-list-item form {
+    display: flex;
+    align-items: center;
+}
+
+.prompt-list-item form button {
+    margin: 0;
+    white-space: nowrap;
+}
+
+.prompt-select {
+    min-width: 0;
+    width: 100%;
+    margin: 0;
+    text-align: left;
+    background: #fdfdfd;
+}
+
+.prompt-select.selected {
+    border-color: #555;
+    background: #ececec;
+    box-shadow: inset 3px 0 0 #555;
+}
+
+.default-prompt-item .prompt-select {
+    border-left-color: #8a6a1f;
+    box-shadow: inset 3px 0 0 #c7a949;
+}
+
+.default-prompt-item .prompt-select.selected {
+    border-color: #8a6a1f;
+    background: #fff8dc;
+    box-shadow: inset 4px 0 0 #8a6a1f;
+}
+
+.prompt-name,
+.prompt-subline {
+    display: block;
+    min-width: 0;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.prompt-name {
+    font-weight: bold;
+}
+
+.prompt-subline {
+    color: #555;
+    font-size: 12px;
+}
+
+.create-drawer {
+    border-top: 1px solid #ddd;
+    padding-top: 0.55rem;
+}
+
+.create-drawer > summary {
+    cursor: pointer;
+    font-weight: bold;
+}
+
+.create-drawer form {
+    display: grid;
+    gap: 0.45rem;
+    margin-top: 0.55rem;
+}
+
+.create-drawer input[type=text],
+.create-drawer select,
+.create-drawer textarea {
+    width: 100%;
+    box-sizing: border-box;
+}
+
+.empty-state,
+.viewer-empty {
+    color: #777;
+    font-style: italic;
+}
+
+.prompt-viewer {
+    display: grid;
+}
+
+.prompt-viewer.is-default-prompt {
+    border-color: #c7a949;
+}
+
+.prompt-viewer.is-default-prompt .viewer-header {
+    border-bottom-color: #c7a949;
+}
+
+.prompt-viewer.is-default-prompt .viewer-title::after {
+    content: " default";
+    margin-left: 0.45rem;
+    padding: 0.08rem 0.35rem;
+    border: 1px solid #c7a949;
+    border-radius: 4px;
+    background: #fff8dc;
+    color: #5a4515;
+    font-size: 12px;
+    font-weight: normal;
+}
+
+.prompt-viewer.is-empty .viewer-shell {
+    display: none;
+}
+
+.prompt-viewer:not(.is-empty) .viewer-empty {
+    display: none;
+}
+
+.viewer-shell {
+    min-height: 0;
+    display: grid;
+    grid-template-rows: auto 1fr;
+    overflow: hidden;
+}
+
+.viewer-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    gap: 0.35rem;
+    padding-bottom: 0.65rem;
+    border-bottom: 1px solid #ddd;
+}
+
+.viewer-title {
+    font-weight: bold;
+    font-size: 1.15rem;
+}
+
+.viewer-content {
+    min-height: 0;
+    overflow: auto;
+    margin: 0.7rem 0 0 0;
+    padding: 0.65rem;
+    border: 1px solid #ccc;
+    background: #fff;
+    white-space: pre-wrap;
+}
+
+#promptModalForm:not(.can-edit) .modal-footer {
+    display: none;
+}
+
+#promptModalForm.read-only-default .modal-title::after {
+    content: " view only";
+    color: #777;
+    font-size: 12px;
+    font-weight: normal;
+}
+
+/* Legacy modal classes, now reused by the inline prompt viewer. */
+
+.modal-backdrop {
+    position: fixed;
+    inset: 0;
+    background: rgba(0, 0, 0, 0.35);
+    display: none;
+    align-items: center;
+    justify-content: center;
+    z-index: 1000;
+}
+
+.modal-backdrop.open {
+    display: flex;
+}
+
+.prompt-modal {
+    width: min(96vw, 1500px);
+    height: min(94vh, 980px);
+    background: white;
+    border: 1px solid #888;
+    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.35);
+    display: flex;
+    flex-direction: column;
+    box-sizing: border-box;
+}
+
+.modal-backdrop.is-default-prompt .prompt-modal {
+    border-color: #8a6a1f;
+}
+
+.modal-backdrop.is-default-prompt .modal-header {
+    background: #fff8dc;
+}
+
+.prompt-modal > form {
+    min-height: 0;
+    flex: 1;
+    display: flex;
+    flex-direction: column;
+}
+
+.modal-header,
+.modal-toolbar,
+.modal-footer {
+    padding: 0.6rem 0.8rem;
+    border-bottom: 1px solid #ddd;
+}
+
+.modal-footer {
+    border-top: 1px solid #ddd;
+    border-bottom: none;
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.5rem;
+}
+
+.modal-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+}
+
+.modal-title {
+    font-weight: bold;
+}
+
+.modal-toolbar {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.5rem;
+}
+
+.modal-body {
+    flex: 1;
+    min-height: 0;
+    display: flex;
+    gap: 0.6rem;
+    padding: 0.6rem;
+    box-sizing: border-box;
+    overflow: hidden;
+}
+
+.edit-pane,
+.version-pane {
+    flex: 1 1 0;
+    min-height: 0;
+    min-width: 0;
+    display: flex;
+    flex-direction: column;
+    gap: 0.4rem;
+}
+
+.content-label {
+    flex: 1;
+    min-height: 0;
+    display: flex;
+    flex-direction: column;
+    overflow: hidden;
+}
+
+.edit-pane textarea {
+    display: block;
+    flex: 1;
+    height: 100%;
+    min-height: 0;
+    resize: none;
+}
+
+.version-content {
+    flex: 1;
+    min-height: 0;
+    overflow: auto;
+    border: 1px solid #ccc;
+    padding: 0.5rem;
+    background: #fafafa;
+    white-space: pre-wrap;
+    font-family: Consolas, "Courier New", monospace;
+}
+
+.modal-form-grid {
+    display: grid;
+    grid-template-columns: 1fr auto;
+    gap: 0.5rem;
+    align-items: end;
+}
+
+.modal-form-grid label {
+    display: block;
+}
+
+.modal-form-grid input[type=text],
+.modal-form-grid select,
+.default-key-row input[type=text] {
+    width: 100%;
+    box-sizing: border-box;
+}
+
+.default-key-row {
+    display: none;
+}
+
+.diff-line {
+    display: block;
+    padding: 0 0.15rem;
+    min-height: 1.25em;
+}
+
+.diff-same {
+    color: #000;
+}
+
+.diff-added {
+    color: #064f16;
+    background: #e7f7e7;
+}
+
+.diff-deleted {
+    color: #8a0000;
+    background: #ffe8e8;
+    text-decoration: line-through;
+}
+
+.diff-changed {
+    color: #5c2380;
+    background: #f2e6ff;
+}
+
+.diff-muted {
+    color: #999;
+}
+
+.version-meta {
+    color: #555;
+    font-size: 12px;
+}
+
+@media (max-width: 900px) {
+    .page-titlebar {
+        grid-template-columns: 1fr;
+        gap: 0.45rem;
+    }
+
+    .header-nav {
+        justify-content: flex-start;
+    }
+
+    .prompt-workbench {
+        grid-template-columns: 1fr;
+        grid-template-rows: minmax(220px, 38vh) minmax(0, 1fr);
+    }
+
+    .modal-body {
+        flex-direction: column;
+    }
+
+    .prompt-modal {
+        width: 98vw;
+        height: 96vh;
+    }
+}
+
+.collapsible-panel > summary {
+    cursor: pointer;
+    font-size: 1.15rem;
+    font-weight: bold;
+    padding: 0.25rem 0;
+}
+
+.collapsible-panel > summary .small {
+    font-weight: normal;
+    margin-left: 0.5rem;
+}
+
+.prompt-preview > summary {
+    cursor: pointer;
+    color: #0645ad;
+}
+
+.prompt-preview pre {
+    max-height: 14rem;
+    overflow: auto;
+    white-space: pre-wrap;
+    background: #fafafa;
+    border: 1px solid #ddd;
+    padding: 0.5rem;
+    margin: 0.4rem 0 0 0;
+}
diff --git a/users.php b/users.php
new file mode 100644
index 0000000..99b93ea
--- /dev/null
+++ b/users.php
@@ -0,0 +1,297 @@
+<?php
+/*
+ * users.php
+ *
+ * Admin user management.
+ */
+
+require_once __DIR__ . '/auth.php';
+require_once __DIR__ . '/header.php';
+require_once __DIR__ . '/languagestore.php';
+require_once __DIR__ . '/usersettings.php';
+
+ini_set('display_errors', '1');
+ini_set('display_startup_errors', '1');
+ini_set('log_errors', '1');
+error_reporting(E_ALL);
+
+$DB_FILE = __DIR__ . '/data/racket-sandbox.sqlite';
+
+$auth = new RacketSandboxAuth($DB_FILE);
+$languageStore = new LanguageStore($DB_FILE);
+$userSettings = new UserSettingsStore($DB_FILE);
+$currentUser = $auth->requireAdminHtml();
+
+$message = '';
+$error = '';
+
+function h($s)
+{
+    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
+}
+
+function t($key, $fallback = null)
+{
+    global $languageStore, $language;
+
+    return $languageStore->translate($key, $language, $fallback);
+}
+
+function post_value($name, $default = '')
+{
+    return $_POST[$name] ?? $default;
+}
+
+function post_bool($name)
+{
+    return isset($_POST[$name]) && $_POST[$name] === '1';
+}
+
+function resolve_user_language($userSettings, $userId, $allowedLanguages)
+{
+    $language = isset($_GET['lang'])
+        ? (string)$_GET['lang']
+        : (string)$userSettings->get($userId, 'language', 'en');
+
+    if (!in_array($language, $allowedLanguages, true)) {
+        $language = 'en';
+    }
+
+    $userSettings->set($userId, 'language', $language);
+
+    return $language;
+}
+
+function fmt_time($ts)
+{
+    if ($ts === null) {
+        return '-';
+    }
+
+    return date('Y-m-d H:i:s', (int)$ts);
+}
+
+$language = resolve_user_language(
+    $userSettings,
+    $currentUser->id(),
+    $languageStore->supportedLanguages()
+);
+
+$languageStore->seedDefaults(array(
+    'app.title' => array('en' => 'Racket sandbox', 'nl' => 'Racket sandbox'),
+    'app.manage_prompts' => array('en' => 'Manage prompts', 'nl' => 'Prompts beheren'),
+    'app.user_management' => array('en' => 'User management', 'nl' => 'Gebruikersbeheer'),
+    'app.logout' => array('en' => 'Logout', 'nl' => 'Uitloggen'),
+    'app.language' => array('en' => 'Language', 'nl' => 'Taal'),
+    'app.logged_in_as' => array('en' => 'Logged in as:', 'nl' => 'Ingelogd als:'),
+    'app.admin' => array('en' => 'Admin', 'nl' => 'Admin'),
+    'app.enabled' => array('en' => 'Enabled', 'nl' => 'Ingeschakeld'),
+    'app.full_name' => array('en' => 'Full name', 'nl' => 'Volledige naam'),
+    'app.email' => array('en' => 'Email', 'nl' => 'E-mail'),
+    'app.password' => array('en' => 'Password', 'nl' => 'Wachtwoord'),
+    'app.new_password' => array('en' => 'New password', 'nl' => 'Nieuw wachtwoord'),
+    'app.created' => array('en' => 'Created', 'nl' => 'Gemaakt'),
+    'app.last_login' => array('en' => 'Last login', 'nl' => 'Laatste login'),
+    'app.actions' => array('en' => 'Actions', 'nl' => 'Acties'),
+    'app.create_user' => array('en' => 'Create user', 'nl' => 'Gebruiker aanmaken'),
+    'app.update_user' => array('en' => 'Update user', 'nl' => 'Gebruiker aanpassen'),
+    'app.change_password' => array('en' => 'Change password', 'nl' => 'Wachtwoord wijzigen'),
+    'app.delete_user' => array('en' => 'Delete user', 'nl' => 'Gebruiker verwijderen'),
+    'app.delete_user_confirm' => array('en' => 'Delete user', 'nl' => 'Gebruiker verwijderen'),
+    'app.cannot_delete_self' => array('en' => 'You cannot delete your own account.', 'nl' => 'Je kunt je eigen account niet verwijderen.'),
+    'app.cannot_disable_self' => array('en' => 'You cannot disable your own account.', 'nl' => 'Je kunt je eigen account niet uitschakelen.'),
+    'app.cannot_remove_own_admin' => array('en' => 'You cannot remove your own admin rights.', 'nl' => 'Je kunt je eigen adminrechten niet verwijderen.'),
+    'app.user_created' => array('en' => 'User created.', 'nl' => 'Gebruiker aangemaakt.'),
+    'app.user_updated' => array('en' => 'User updated.', 'nl' => 'Gebruiker aangepast.'),
+    'app.password_changed' => array('en' => 'Password changed.', 'nl' => 'Wachtwoord gewijzigd.'),
+    'app.user_deleted' => array('en' => 'User deleted.', 'nl' => 'Gebruiker verwijderd.'),
+    'app.back_to_sandbox' => array('en' => 'Back to Racket sandbox', 'nl' => 'Terug naar Racket sandbox'),
+    'app.configuration' => array('en' => 'Configuration', 'nl' => 'Configuratie'),
+));
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    $action = post_value('action');
+
+    try {
+        if ($action === 'logout') {
+            $auth->logout();
+            header('Location: /login.php');
+            exit;
+        } elseif ($action === 'create_user') {
+            $auth->createUser(
+                post_value('email'),
+                post_value('full_name'),
+                post_value('password'),
+                post_bool('is_admin'),
+                post_bool('is_enabled')
+            );
+            $message = t('app.user_created', 'User created.');
+        } elseif ($action === 'update_user') {
+            $userId = (int)post_value('user_id');
+            $isAdmin = post_bool('is_admin');
+            $isEnabled = post_bool('is_enabled');
+
+            if ($userId === $currentUser->id() && !$isAdmin) {
+                throw new Exception(t('app.cannot_remove_own_admin', 'You cannot remove your own admin rights.'));
+            }
+
+            if ($userId === $currentUser->id() && !$isEnabled) {
+                throw new Exception(t('app.cannot_disable_self', 'You cannot disable your own account.'));
+            }
+
+            $auth->updateUser($userId, post_value('email'), post_value('full_name'));
+            $auth->setAdmin($userId, $isAdmin);
+            $auth->setEnabled($userId, $isEnabled);
+            $message = t('app.user_updated', 'User updated.');
+        } elseif ($action === 'set_password') {
+            $auth->setPassword(post_value('email'), post_value('password'));
+            $message = t('app.password_changed', 'Password changed.');
+        } elseif ($action === 'delete_user') {
+            $userId = (int)post_value('user_id');
+
+            if ($userId === $currentUser->id()) {
+                throw new Exception(t('app.cannot_delete_self', 'You cannot delete your own account.'));
+            }
+
+            $auth->deleteUser($userId);
+            $message = t('app.user_deleted', 'User deleted.');
+        }
+    } catch (Throwable $e) {
+        $error = $e->getMessage();
+    }
+}
+
+$users = $auth->listUsers();
+$headerLanguages = array();
+
+foreach ($languageStore->supportedLanguages() as $lang) {
+    $headerLanguages[$lang] = $languageStore->languageLabel($lang);
+}
+
+header('Content-Type: text/html; charset=utf-8');
+?>
+<!doctype html>
+<html lang="<?= h($language) ?>">
+<head>
+<meta charset="utf-8">
+<title><?= h(t('app.user_management', 'User management')) ?></title>
+<link rel="stylesheet" href="/styles.css">
+</head>
+<body>
+
+<div class="page">
+
+<?php
+render_app_header(array(
+    'title' => t('app.user_management', 'User management'),
+    'nav_items' => array(
+        array('label' => t('app.back_to_sandbox', 'Back to Racket sandbox'), 'url' => '/?lang=' . rawurlencode($language)),
+        array(
+            'label' => t('app.manage_prompts', 'Manage prompts'),
+            'url' => '/prompts?lang=' . rawurlencode($language),
+            'separator_before' => true,
+        ),
+        array(
+            'label' => t('app.user_management', 'User management'),
+            'url' => '/users?lang=' . rawurlencode($language),
+            'active' => true,
+            'separator_before' => true,
+        ),
+        array(
+            'label' => t('app.configuration', 'Configuration'),
+            'url' => '/admin-config?lang=' . rawurlencode($language),
+            'separator_before' => true,
+        ),
+    ),
+    'user' => $currentUser,
+    'user_prefix' => t('app.logged_in_as', 'Logged in as:'),
+    'admin_label' => t('app.admin', 'Admin'),
+    'language_label' => t('app.language', 'Language'),
+    'language' => $language,
+    'languages' => $headerLanguages,
+    'language_action' => '/users',
+    'logout_action' => '/users?lang=' . rawurlencode($language),
+    'logout_label' => t('app.logout', 'Logout'),
+    'message' => $message,
+    'error' => $error,
+));
+?>
+
+<main class="page-main dashboard-main">
+
+<section class="panel">
+<h2><?= h(t('app.create_user', 'Create user')) ?></h2>
+
+<form method="post" action="/users?lang=<?= h($language) ?>" class="admin-form-grid">
+<input type="hidden" name="action" value="create_user">
+<label><?= h(t('app.full_name', 'Full name')) ?><br><input type="text" name="full_name" required></label>
+<label><?= h(t('app.email', 'Email')) ?><br><input type="email" name="email" required></label>
+<label><?= h(t('app.password', 'Password')) ?><br><input type="password" name="password" autocomplete="new-password" required></label>
+<label><input type="checkbox" name="is_admin" value="1"> <?= h(t('app.admin', 'Admin')) ?></label>
+<label><input type="checkbox" name="is_enabled" value="1" checked> <?= h(t('app.enabled', 'Enabled')) ?></label>
+<button type="submit"><?= h(t('app.create_user', 'Create user')) ?></button>
+</form>
+</section>
+
+<section class="panel">
+<h2><?= h(t('app.user_management', 'User management')) ?></h2>
+
+<table>
+<thead>
+<tr>
+<th><?= h(t('app.full_name', 'Full name')) ?></th>
+<th><?= h(t('app.email', 'Email')) ?></th>
+<th><?= h(t('app.admin', 'Admin')) ?></th>
+<th><?= h(t('app.enabled', 'Enabled')) ?></th>
+<th><?= h(t('app.created', 'Created')) ?></th>
+<th><?= h(t('app.last_login', 'Last login')) ?></th>
+<th><?= h(t('app.actions', 'Actions')) ?></th>
+</tr>
+</thead>
+<tbody>
+<?php foreach ($users as $managedUser): ?>
+<tr>
+<td colspan="7">
+<form method="post" action="/users?lang=<?= h($language) ?>" class="user-row-form">
+<input type="hidden" name="action" value="update_user">
+<input type="hidden" name="user_id" value="<?= h($managedUser->id()) ?>">
+
+<label><?= h(t('app.full_name', 'Full name')) ?><br><input type="text" name="full_name" value="<?= h($managedUser->fullName()) ?>" required></label>
+<label><?= h(t('app.email', 'Email')) ?><br><input type="email" name="email" value="<?= h($managedUser->email()) ?>" required></label>
+<label><input type="checkbox" name="is_admin" value="1" <?= $managedUser->isAdmin() ? 'checked' : '' ?>> <?= h(t('app.admin', 'Admin')) ?></label>
+<label><input type="checkbox" name="is_enabled" value="1" <?= $managedUser->isEnabled() ? 'checked' : '' ?>> <?= h(t('app.enabled', 'Enabled')) ?></label>
+<span><?= h(fmt_time($managedUser->createdAt())) ?></span>
+<span><?= h(fmt_time($managedUser->lastLoginAt())) ?></span>
+<button type="submit"><?= h(t('app.update_user', 'Update user')) ?></button>
+</form>
+
+<div class="user-row-actions">
+<form method="post" action="/users?lang=<?= h($language) ?>">
+<input type="hidden" name="action" value="set_password">
+<input type="hidden" name="email" value="<?= h($managedUser->email()) ?>">
+<label><?= h(t('app.new_password', 'New password')) ?><br><input type="password" name="password" autocomplete="new-password"></label>
+<button type="submit"><?= h(t('app.change_password', 'Change password')) ?></button>
+</form>
+
+<?php if ($managedUser->id() !== $currentUser->id()): ?>
+<form method="post" action="/users?lang=<?= h($language) ?>"
+      onsubmit="return confirm('<?= h(t('app.delete_user_confirm', 'Delete user')) ?> <?= h($managedUser->email()) ?>?');">
+<input type="hidden" name="action" value="delete_user">
+<input type="hidden" name="user_id" value="<?= h($managedUser->id()) ?>">
+<button type="submit"><?= h(t('app.delete_user', 'Delete user')) ?></button>
+</form>
+<?php else: ?>
+<p class="small"><?= h(t('app.cannot_delete_self', 'You cannot delete your own account.')) ?></p>
+<?php endif; ?>
+</div>
+</td>
+</tr>
+<?php endforeach; ?>
+</tbody>
+</table>
+</section>
+
+</main>
+</div>
+</body>
+</html>
diff --git a/usersettings.php b/usersettings.php
new file mode 100644
index 0000000..2db85dc
--- /dev/null
+++ b/usersettings.php
@@ -0,0 +1,111 @@
+<?php
+/*
+ * usersettings.php
+ *
+ * Tiny SQLite-backed key/value store for per-user UI preferences.
+ */
+
+class UserSettingsStoreException extends Exception
+{
+}
+
+class UserSettingsStore
+{
+    private $db;
+
+    public function __construct($dbFile)
+    {
+        $dir = dirname($dbFile);
+
+        if (!is_dir($dir)) {
+            if (!mkdir($dir, 0700, true)) {
+                throw new UserSettingsStoreException('Could not create database directory: ' . $dir);
+            }
+        }
+
+        $this->db = new PDO('sqlite:' . $dbFile);
+        $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+        $this->db->exec('PRAGMA journal_mode = WAL');
+        $this->db->exec('PRAGMA busy_timeout = 5000');
+
+        $this->init();
+    }
+
+    private function init()
+    {
+        $this->db->exec(
+            'CREATE TABLE IF NOT EXISTS user_settings (
+                user_id INTEGER NOT NULL,
+                setting_key TEXT NOT NULL,
+                setting_value TEXT NOT NULL,
+                created_at INTEGER NOT NULL,
+                updated_at INTEGER NOT NULL,
+                PRIMARY KEY(user_id, setting_key)
+            )'
+        );
+    }
+
+    public function get($userId, $key, $default = null)
+    {
+        $stmt = $this->db->prepare(
+            'SELECT setting_value
+             FROM user_settings
+             WHERE user_id = :user_id
+               AND setting_key = :setting_key'
+        );
+        $stmt->execute(array(
+            ':user_id' => $this->safeUserId($userId),
+            ':setting_key' => $this->safeKey($key),
+        ));
+
+        $row = $stmt->fetch(PDO::FETCH_ASSOC);
+
+        return $row ? (string)$row['setting_value'] : $default;
+    }
+
+    public function set($userId, $key, $value)
+    {
+        $now = time();
+
+        $stmt = $this->db->prepare(
+            'INSERT INTO user_settings
+             (user_id, setting_key, setting_value, created_at, updated_at)
+             VALUES
+             (:user_id, :setting_key, :setting_value, :created_at, :updated_at)
+             ON CONFLICT(user_id, setting_key)
+             DO UPDATE SET
+                setting_value = excluded.setting_value,
+                updated_at = excluded.updated_at'
+        );
+
+        $stmt->execute(array(
+            ':user_id' => $this->safeUserId($userId),
+            ':setting_key' => $this->safeKey($key),
+            ':setting_value' => (string)$value,
+            ':created_at' => $now,
+            ':updated_at' => $now,
+        ));
+    }
+
+    private function safeUserId($userId)
+    {
+        $userId = (int)$userId;
+
+        if ($userId <= 0) {
+            throw new UserSettingsStoreException('Invalid user id.');
+        }
+
+        return $userId;
+    }
+
+    private function safeKey($key)
+    {
+        $key = trim((string)$key);
+
+        if (!preg_match('/^[a-z0-9_.-]{1,80}$/', $key)) {
+            throw new UserSettingsStoreException('Invalid setting key.');
+        }
+
+        return $key;
+    }
+}