Add user authentication and account management system

Features:
- User registration with username, email, password
- Login with JWT token authentication
- Password hashing with BCrypt
- Account settings & management
- Device linking to accounts
- Change password & password reset
- Account-User relationship (1-to-1 with game data)

Database entities:
- Account: User accounts with credentials
- DeviceAccount: Link devices to accounts (many-to-many)

API endpoints:
- POST /api/auth/register
- POST /api/auth/login
- POST /api/auth/change-password
- POST /api/auth/forgot-password
- POST /api/auth/reset-password
- GET /api/auth/me
- POST /api/auth/link-device
- DELETE /api/auth/unlink-device/{deviceId}

Starting resources for new accounts:
- 100,000 Gold
- 500,000 Cash
- Level 1

Ready for VPS deployment with HTTPS.

RR3CommunityServer/Program.cs

@@ -20,6 +20,7 @@ builder.Services.AddScoped<ISessionService, SessionService>();
 builder.Services.AddScoped<IUserService, UserService>();
 builder.Services.AddScoped<ICatalogService, CatalogService>();
 builder.Services.AddScoped<IDrmService, DrmService>();
+builder.Services.AddScoped<IAuthService, AuthService>();
 builder.Services.AddScoped<AssetExtractionService>();
 
 // CORS for cross-origin requests