Fix move_memory after migration timestamp collision

Two migrations sharing the same 20260621000003 timestamp caused one to be rejected when pushed to the database. This release ships a new migration that applies the missing move_memory fix from issue #283 (destination-space membership guard, topic reassignment to the General Topic on move) on top of the updated_at fixes from issue #302, ensuring all metadata-only RPCs leave updated_at unchanged and that moving a Memory into a shared Space lands it in a valid Topic bucket.