Uploads now land in temp/desktop_uploads/<sid>/ instead of a flat dir, so a
session's attachments can be cleaned up when the session is deleted.
- upload_handler reads `sid` from the body and saves under desktop_uploads/<sid>/
(sanitized; missing sid -> _misc bucket).
- delete_session purges the session's upload subdir.
- _sweep_stale_uploads recurses into sid subdirs (rglob) and drops empty dirs.
- Frontend: uploadOne sends the active session's bridgeSessionId; addFiles
ensures a session exists (reusing newSession/ensureBridgeSession) before
uploading, so a sid is available — the empty-app case creates one first.
Whitelist checks (upload_raw / upload_delete) already validate "under root",
so the deeper subdir paths pass unchanged.
dd3xp
bab5dec66f
