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

bin/.env

@@ -4,10 +4,12 @@ JWT_SECRET=your-super-secret-key-change-me
 # Secret pepper added to passwords before hashing (should be random and kept secret)
 PASSWORD_PEPPER=your-random-pepper-string-change-me
 # Database connection settings
-POSTGRES_HOST="db"
+POSTGRES_HOST="localhost"
 POSTGRES_PORT="5432"
 POSTGRES_DB="family_safety"
 POSTGRES_USER="postgres"
 POSTGRES_PASSWORD="postgres"
 # TOKEN_LIFETIME in minutes
-TOKEN_LIFETIME=600
+TOKEN_LIFETIME=600
+# Secret key for registration (MD5 hash of this key must be sent by the user)
+REGISTRATION_SECRET_KEY=FtracKer*1405.