* fix(mobile): dedupe stale remote_asset rows on sync
queue a pre-delete on the matching partial-index tuple before each
upsert in updateAssetsV1/V2 so the second insert does not crash on
SqliteException(2067) when the server re-issues a new id for the
same (ownerId, checksum). closes#22522#27186.
* run the dedupe deletes before the inserts and keep only the last duplicate per payload
* switch the asset upsert to insert or replace
* trim the dedupe tests to the essentials