When better-sqlite3 native module isn't installed/buildable, the adapter
now falls back to an in-memory mock implementation. This allows development
and testing without native compilation.
TASK-007A: LocalSQL Adapter (Phase 5/Phase 11 shared foundation)
- Add LocalSQLAdapter implementing CloudStore interface with SQLite backend
- Add QueryBuilder for Parse-style query to SQL translation
- Add SchemaManager for table creation, migrations, and exports
- Support all CloudStore methods: query, fetch, create, save, delete
- Support aggregate, distinct, increment, count operations
- Support relations via junction tables
- Add schema export to PostgreSQL and Supabase formats
- Add comprehensive unit tests for QueryBuilder
This adapter enables:
- Local offline database for development
- Foundation for Phase 11 execution history storage
- Schema migration path to production databases
