feat: replace SFTP drop with Syncthing share path

Remove SFTPGo; mount event data from the Syncthing folder, watch
incoming/, and name variants after the source stem.

Co-authored-by: Cursor <cursoragent@cursor.com>

NOTES.md

@@ -4,7 +4,14 @@
 
 - Live on boka: `/home/frank/live.f12.rocks`
 - Web: https://live.f12.rocks
-- SFTP: `livef12@frank-schwenk.de` port **12121** (spec 121212 is invalid TCP)
-- Password in server `.env` only (`chmod 600`); ntfy sent to phone
-- Data: `/home/frank/live.f12.rocks/data` (inbox not auto-cleaned)
+- Password / secrets in server `.env` only (`chmod 600`)
 - First rembg job downloads ~176 MB model into docker volume `rembg_cache`
+
+## Syncthing cutover (2026-07-18)
+
+- SFTPGo removed; drop path is Syncthing
+- Data share: `/home/frank/sync.schwenk.online/data/livef12`
+  (`incoming/` + `jobs/` + `processed.json`)
+- Old path `/home/frank/live.f12.rocks/data` no longer used by compose
+  (migration/cleanup manual)
+- Host port 12121 can be closed after cutover