* Support `attachMetadatabase` in previewsPreviews can currently crash if an app database is provisioned thatattaches a metadatabase. Despite trying to ensure all databases arein-memory to work around an Xcode previews quirk, SQLite still throws afile system error when connecting to an in-memory database with a fileURL.This PR attempts to work around the issue by sharing the same databaseconnection in previews.This does require losing the internal `DatabaseMigrator` we currentlyuse for the metadatabase and instead depend on `IF NOT EXISTS` becauseGRDB only supports a single set of migrations per database (we couldmaybe scope this change just to previews), but this is probably OK. Italso means that the migrator will always detect schema changes forpreviews since the metadatabase tables will conflict, but this is alsoprobably OK since previews are not long-living.* Revert "Support `attachMetadatabase` in previews"This reverts commit1734711.* wip* wip* wip* wip---------Co-authored-by: Brandon Williams <mbrandonw@hey.com>

* Introduce `SyncMetadata.ID`* wip* wip

* Use metadatabase to query sync metadata.* Added a test* dont attach metadatabase for base suite.* add test for attached metadatabase

* Restrict mutation to sync metadata fields.* wip* wip

* Fix bug that reset timestamp of record when sharing.* wip* Clean up'* clean up* wip* test

* Methods to explicitly fetch and send changes.* docs* Fix typos in SyncEngine documentation commentsCorrected typos in documentation comments for sync methods.* Fix apostrophe formatting in documentation comments---------Co-authored-by: Stephen Celis <stephen@stephencelis.com>

* Fix issues with `CK{Record,Share}.SystemFieldsRepresentation`I'm a little surprised that this diff fixes things, but it does locallyfor me, in the latest Xcode 26, so let's test this change a bit beforemerging.* Compile time tests* wip;* wip---------Co-authored-by: Brandon Williams <mbrandonw@hey.com>