[Feature] Detect assets removed from upload/library or allow mobile uploads directly to External Libraries

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request. • Yes The feature Description I want to use the Android app both for photo backup and as a convenient way to transfer photos from my phone to my main photo library. Uploaded photos are stored in: /upload/library/... After upload, when I have the time, I move the files from the upload-folder to their desired location: • Folders outside of Immich (typically document or archive storage). • Folders that are configured as an External Library in Immich (my main photo library). Current behavior When files are moved out of /upload/library, Immich continues to show the assets even though the original files no longer exist at their recorded location. This leaves stale assets in the library. However, when files are moved or removed from an External Library, Immich detects the change during library scans and moves the assets to Trash. …