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/Application/Contact/commands/CreateContactCommandHandler.ts

@@ -0,0 +1,26 @@
+import { IContactRepository } from '../../../Domain/IRepository/IContactRepository';
+import { CreateContactCommand } from './CreateContactCommand';
+import { ShortContactDto } from '../../DTOs/ContactDto';
+import { ContactAggregate, ContactState } from '../../../Domain/Contact/ContactAggregate';
+import { ContactMapper } from '../../DTOs/Mappers/ContactMapper';
+
+export class CreateContactCommandHandler {
+  constructor(private readonly contactRepo: IContactRepository) {}
+
+  async execute(cmd: CreateContactCommand): Promise<ShortContactDto> {
+    try {
+      const contact = new ContactAggregate();
+      contact.name = cmd.name;
+      contact.email = cmd.email;
+      contact.userid = cmd.userid || null;
+      contact.type = cmd.type;
+      contact.txt = cmd.txt;
+      contact.state = ContactState.ACTIVE;
+      
+      const created = await this.contactRepo.create(contact);
+      return ContactMapper.toShortDto(created);
+    } catch (error) {
+      throw new Error('Failed to create contact');
+    }
+  }
+}