Add phone album sync to the Android client: MediaStore source (device
albums), a Room index with upload provenance, on-device previews, and a
mixed server + device album list where a linked pair collapses into a
single device card with a link indicator and mode label.
Three modes over one pipeline: A (off), B (upload copies, originals stay
local), C (upload originals and offload them locally to previews). The
sync engine tracks device changes (add/remove/rename/move/content), matches
assets to server photos by sha256 content hash, deletes only this client's
uploads, and reflects server changes without touching local originals.
Offload is automatic; the zoomed viewer pulls the server original.
Backend: expose the original content checksum in photo data (Postgres and
SQLite), additive with no migration.
Also anchor the `.gitignore` `data/` rule to `/data/` so the Android
`com.galo.android.data` package is tracked, and add the halo launcher icon.
iu
38b5b03f59