Joplin: Path traversal in transcribe proxy endpoint via URL-encoded slash

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.7, the GET /api/transcribe/:id and POST /api/transcribe/:id handlers in packages/server/src/routes/api/transcribe.ts on Joplin Server instances with TRANSCRIBE_ENABLED=true pass the decoded id directly into transcription backend URLs. An authenticated user can place URL-encoded slash and parent-directory segments in the job ID, causing parseSubPath() to decode a path that escapes the intended /transcribe/ prefix. The server then proxies the request to other transcription-backend endpoints and can return their responses, potentially exposing internal administrative, health, or configuration data. This issue is fixed in version 3.7.7.