DatabaseService gains a testable init(dbQueue:) plus a makeInMemory()
convenience and schema-introspection helpers (tableExists/columnNames),
so migration tests don't need the test target to import GRDB directly.
ContextSelectionService now takes an injected DatabaseService (defaults
to .shared) and its DB-coupled methods (smartSelection,
getSummariesForExcludedRange, isMessageStarred) are bumped to internal.
No logic changes to existing call sites.
rune
c6a7439648