Complete backend MVP

docs/DATABASE_SCHEMA.md

@@ -1,6 +1,6 @@
 # Visione Database Schema
 
-The schema is stored in `migrations/001_initial_schema.sql`.
+The schema is stored in ordered SQL migrations under `migrations/`.
 
 Persistence currently uses `drogon::orm::DbClient` with raw parameterized SQL.
 The project does not use Drogon generated models or `Mapper<T>` while the schema
@@ -23,6 +23,9 @@ Important tables:
 - `messages`: citizen/operator report conversation.
 - `feedback`: citizen rating and comment after resolution.
 - `reward_events`: indirect gamification points ledger.
+- `notifications`: local in-app notifications for status changes, messages and
+  reward events.
+- `moderation_flags`: report/message review queue for abusive or invalid content.
 
 GeoJSON is intentionally used instead of MySQL Spatial in milestone 1 to keep
 the local setup simple and portable.