feat: add Swagger UI docs, custom CORS middleware, and request logging

- Add Swagger UI files and updated API spec for Family Safety Tracker
- Replace shelf_cors_headers with custom CORS middleware in server.dart
- Add request_logger middleware with timing for auth and geo routes
- Add REGISTRATION_SECRET_KEY to .env for registration validation
- Remove postgres port exposure from docker-compose.yml
- Update opencode.json model configuration
- Add crypto dependency and update Flutter web assets

docker-compose.yml

@@ -9,8 +9,6 @@ services:
       POSTGRES_USER: postgres
       POSTGRES_PASSWORD: postgres
       POSTGRES_DB: family_safety
-    ports:
-      - "5432:5432"
     volumes:
       - postgres_data:/var/lib/postgresql/data
     healthcheck: