Move rendering into private templates

Add an explicit template renderer with HTML views and partials for the app, bootstrap, package, and catalog pages. Move shared reporting setup into config/reporting.php and relocate stylesheet assets under css/.

private/views/partials/prompt-create-default.html

@@ -0,0 +1,15 @@
+<details class="create-drawer">
+<summary>{{create_default_label}}</summary>
+<form method="post" action="/prompts?lang={{language_url}}&mode=defaults">
+<input type="hidden" name="action" value="create_default">
+<label>{{default_key_label}}<br><input type="text" name="default_key" placeholder="bootstrap-racket"></label>
+<label>{{name_label}}<br><input type="text" name="name"></label>
+<label>{{language_label}}<br>
+<select name="language">
+{{{language_options_html}}}
+</select>
+</label>
+<label>{{prompt_content_label}}<br><textarea name="content" rows="7"></textarea></label>
+<button type="submit">{{create_default_label}}</button>
+</form>
+</details>