* fix(mobile): show the real date for android local photos with no exif
photos with no exif date showed their copy-to-phone date in the "on this device" albums instead of the real date. fall back to the earlier of date_modified/date_added (matches the server + ios), plus a migration to fix the rows already saved wrong.
* persist migration progress when the date backfill fails
* fix local date migration for trash and epoch rows
* cover epoch dates in both local asset tables
* simplify the created date pick and rework the migration test
* heal no-exif dates from mediastore in the v27 migration
* check gallery access from dart and skip dates that do not parse
* let the date heal run once and never block the version
* read the trashed assets through the same cast the sync uses