No places.

private/util.rkt

@@ -17,6 +17,7 @@
          filesystem-path
          flac-path?
          opus-path?
+         manager-temp-path?
          directory-file-paths
          replace-path-extension
          ensure-parent-directory!
@@ -112,6 +113,16 @@
 (define (file-exists?/quiet p)
   (with-handlers ([exn:fail? (lambda (_) #f)]) (file-exists? p)))
 
+(define (path-file-name-string p)
+  (let-values ([(base name dir?) (split-path p)])
+    (and (path? name) (path->string name))))
+
+(define (manager-temp-path? p)
+  (define name (path-file-name-string p))
+  (and name
+       (string-prefix? name ".")
+       (regexp-match? #rx"\\.tmp-[0-9.]+\\.(flac|opus)$" name)))
+
 (define (flac-path? p)
   (and (file-exists?/quiet p) (extension-ci=? p ".flac")))