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

SerpentRace_Backend/src/Domain/IRepository/IGameRepository.ts

@@ -0,0 +1,14 @@
+import { GameAggregate } from '../Game/GameAggregate';
+import { IPaginatedRepository } from './IBaseRepository';
+
+export interface IGameRepository extends IPaginatedRepository<GameAggregate, { games: GameAggregate[], totalCount: number }> {
+    // Game-specific methods
+    findByGameCode(gamecode: string): Promise<GameAggregate | null>;
+    findActiveGames(): Promise<GameAggregate[]>;
+    findGamesByPlayer(playerId: string): Promise<GameAggregate[]>;
+    findWaitingGames(): Promise<GameAggregate[]>;
+    findFinishedGames(from?: number, to?: number): Promise<{ games: GameAggregate[], totalCount: number }>;
+    addPlayerToGame(gameId: string, playerId: string): Promise<GameAggregate | null>;
+    removePlayerFromGame(gameId: string, playerId: string): Promise<GameAggregate | null>;
+    updateGameState(gameId: string, started: boolean, finished?: boolean, winner?: string): Promise<GameAggregate | null>;
+}