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/IDeckRepository.ts

@@ -0,0 +1,9 @@
+import { DeckAggregate } from '../Deck/DeckAggregate';
+import { IPaginatedRepository } from './IBaseRepository';
+
+export interface IDeckRepository extends IPaginatedRepository<DeckAggregate, { decks: DeckAggregate[], totalCount: number }> {
+    // Deck-specific methods for restrictions and filtering
+    countActiveByUserId(userId: string): Promise<number>;
+    countOrganizationalByUserId(userId: string): Promise<number>;
+    findFilteredDecks(userId: string, userOrgId?: string | null, isAdmin?: boolean, from?: number, to?: number): Promise<{ decks: DeckAggregate[], totalCount: number }>;
+}