Backend Complete: Interface Refactoring & Service Container Enhancements

Repository Interface Optimization:
- Created IBaseRepository.ts and IPaginatedRepository.ts
- Refactored all 7 repository interfaces to extend base interfaces
- Eliminated ~200 lines of redundant code (70% reduction)
- Improved type safety and maintainability

 Dependency Injection Improvements:
- Added EmailService and GameTokenService to DIContainer
- Updated CreateUserCommandHandler constructor for DI
- Updated RequestPasswordResetCommandHandler constructor for DI
- Enhanced testability and service consistency

 Environment Configuration:
- Created comprehensive .env.example with 40+ variables
- Organized into 12 logical sections (Database, Security, Email, etc.)
- Added security guidelines and best practices
- Documented all backend environment requirements

 Documentation:
- Added comprehensive codebase review
- Created refactoring summary report
- Added frontend implementation guide

Impact: Improved code quality, reduced maintenance overhead, enhanced developer experience

Documentations/PGADMIN_GUIDE.md

@@ -0,0 +1,117 @@
+# pgAdmin Database Administration Guide
+
+## Access pgAdmin
+
+- **URL**: http://localhost:8080
+- **Email**: admin@serpentrace.dev  
+- **Password**: admin
+
+## Pre-configured Server
+
+The pgAdmin interface should have a pre-configured server named **"SerpentRace PostgreSQL Dev"** in the "Development" group.
+
+## Manual Server Configuration (If Needed)
+
+If the server is not automatically configured, add it manually:
+
+### Server Details
+- **Name**: SerpentRace PostgreSQL Dev
+- **Host**: postgres (or localhost if connecting from outside Docker)
+- **Port**: 5432
+- **Database**: serpentrace
+- **Username**: postgres
+- **Password**: postgres
+
+### Steps to Add Server Manually
+
+1. Right-click on "Servers" in the left panel
+2. Select "Register" > "Server..."
+3. Fill in the "General" tab:
+   - Name: `SerpentRace PostgreSQL Dev`
+   - Server group: `Development`
+4. Fill in the "Connection" tab:
+   - Host name/address: `postgres`
+   - Port: `5432`
+   - Maintenance database: `serpentrace`
+   - Username: `postgres`
+   - Password: `postgres`
+5. Click "Save"
+
+## Common Database Operations
+
+### View Tables
+1. Expand the server connection
+2. Expand "Databases" > "serpentrace"
+3. Expand "Schemas" > "public"
+4. Expand "Tables"
+
+### Run SQL Queries
+1. Right-click on the database name
+2. Select "Query Tool"
+3. Write your SQL queries in the editor
+4. Click the "Execute" button or press F5
+
+### View Data
+1. Right-click on any table
+2. Select "View/Edit Data" > "All Rows"
+
+## Troubleshooting
+
+### Connection Issues
+- Ensure Docker containers are running: `docker ps`
+- Check container logs: `docker logs serpentrace-postgres-dev`
+- Test connections: `npm run test:connections`
+
+### Authentication Failed
+- Verify the password is correct: `postgres`
+- Check if you're using the correct hostname: `postgres` (inside Docker) vs `localhost` (outside Docker)
+
+### Server Not Appearing
+- Restart pgAdmin container:
+  ```bash
+  docker-compose -f docker-compose.dev.yml restart pgadmin
+  ```
+- Clear browser cache and reload
+
+## Development Tips
+
+### Useful SQL Queries
+
+```sql
+-- List all tables
+SELECT table_name FROM information_schema.tables 
+WHERE table_schema = 'public';
+
+-- Check database size
+SELECT pg_size_pretty(pg_database_size('serpentrace'));
+
+-- View active connections
+SELECT * FROM pg_stat_activity WHERE datname = 'serpentrace';
+
+-- Check migration status (if using TypeORM)
+SELECT * FROM migrations ORDER BY timestamp DESC;
+```
+
+### Database Backup
+1. Right-click on database name
+2. Select "Backup..."
+3. Choose format (Custom recommended for pgAdmin restore)
+4. Set filename and location
+5. Click "Backup"
+
+### Database Restore
+1. Right-click on "Databases"
+2. Select "Restore..."
+3. Choose the backup file
+4. Configure options as needed
+5. Click "Restore"
+
+## Security Notes
+
+⚠️ **Development Only**: The current configuration uses default credentials and is intended for development only. For production:
+
+- Use strong, unique passwords
+- Enable SSL connections
+- Restrict network access
+- Use environment variables for credentials
+- Enable authentication and authorization features