Fix SQLite threading bug, correct FTP upload path

- Add check_same_thread=False to SQLite connection (watchdog
  callbacks run in a separate thread)
- Camera upload dir is /data/photos/incoming (not /incoming)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -53,7 +53,7 @@ Configure an FTP profile on the camera:
 | Passive Mode    | **ON**                   |
 | Username        | `fujiftp`                |
 | Password        | *(your password)*        |
-| Upload Dir      | `/incoming`              |
+| Upload Dir      | `/data/photos/incoming`  |
 | Auto Transfer   | ON (or manual trigger)   |
 
 > **Note**: Bij FTPS kun je via **FTP OPTIONAL SETTING → ROOT CERTIFICATE** een self-signed root certificaat laden als je NAS er een gebruikt.