Fix pipeline shutdown hang, delete path safety, organize folder scoping, journal duplication; add PHOTON.app menu-bar launcher

- Stop/pause could block the downscale thread for up to 60s and throw an
  unhandled exception on shutdown; queue puts are now stop-aware
- /api/delete_photo(s) now refuse to delete anything outside the
  configured photo folder
- organize_alias used a stale startup-time default folder instead of the
  folder actually being scanned/tagged
- journal_write is append-only, so retagging a photo left stale duplicate
  lines that inflated category counts and search results; reads now dedupe
  by path and the journal is compacted once on startup
- batch delete now does one journal rewrite for the whole set instead of
  one per file
- add PHOTON.app: a signed, dependency-free Swift menu-bar app that starts
  server.py in the background (or attaches to an already-running instance),
  opens the console, and exposes Open/Restart/Stop/Show Log/Quit

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitignore

@@ -6,4 +6,6 @@ photon_audits.jsonl
 photon_phash.json
 photon_folder.json
 photon_categories.json
+.photon.pid
+.photon_server.log
 .claude/