Add local data store adapter layer and Hive scaffold

docs/SETUP.md

@@ -22,6 +22,20 @@ Use fake gateway for local/offline development:
 flutter run --dart-define=USE_FAKE_BACKEND=true
 ```
 
+## Local Persistence Backend
+
+Default local store:
+
+- `shared_preferences` (stable baseline)
+
+Optional migration path:
+
+```bash
+flutter run --dart-define=USE_HIVE_LOCAL_DB=true
+```
+
+When enabled, local app state is stored in Hive via the `LocalDataStore` adapter layer.
+
 ## Run Tests
 
 ```bash

docs/progress.md

@@ -2,6 +2,29 @@
 
 Updated: 2026-02-15
 
+## Latest Milestone (2026-02-15): Local Store Adapter Layer (DB Migration Scaffold)
+
+Implemented a persistence boundary so local app state is no longer tightly coupled to `shared_preferences` internals:
+
+- Added local persistence abstraction:
+  - `lib/features/local/storage/local_data_store.dart`
+  - `LocalDataStore` + `LocalDataRecord`
+- Added concrete store implementations:
+  - `lib/features/local/storage/local_data_store_shared_prefs.dart`
+  - `lib/features/local/storage/local_data_store_hive.dart`
+  - `lib/features/local/storage/local_data_store_in_memory.dart`
+  - provider wiring: `lib/features/local/storage/local_data_store_provider.dart`
+- Refactored local repository to use store adapter:
+  - `lib/features/local/local_repository.dart`
+  - build/read/write/migration paths now go through `LocalDataStore`
+  - schema migration hook retained and now store-agnostic
+- Added config flag for local backend selection:
+  - `lib/core/config/app_config.dart` -> `USE_HIVE_LOCAL_DB`
+- Added setup docs for switching local persistence backend:
+  - `docs/SETUP.md`
+
+This prepares the app for a true DB migration path while keeping existing UX and tests stable.
+
 ## Latest Milestone (2026-02-15): Cross-View Responsive Pass
 
 Audited and adjusted the main product views for mobile-first behavior while preserving desktop/web UX: