Implement LLM provider configuration and update user settings

- Added functionality to update the default LLM provider for users via a new endpoint in UserController.
- Introduced LlmProvider enum to manage available LLM options: Auto, Gemini, OpenAI, and Claude.
- Updated User and UserEntity models to include DefaultLlmProvider property.
- Enhanced database context and migrations to support the new LLM provider configuration.
- Integrated LLM services into the application bootstrap for dependency injection.
- Updated TypeScript API client to include methods for managing LLM providers and chat requests.

src/Managing.Application.Abstractions/Services/IUserService.cs

@@ -12,6 +12,7 @@ public interface IUserService
     Task<User> UpdateAgentName(User user, string agentName);
     Task<User> UpdateAvatarUrl(User user, string avatarUrl);
     Task<User> UpdateTelegramChannel(User user, string telegramChannel);
+    Task<User> UpdateDefaultLlmProvider(User user, LlmProvider defaultLlmProvider);
     Task<User> UpdateUserSettings(User user, UserSettingsDto settings);
     Task<User> GetUserByName(string name);
     Task<User> GetUserByAgentName(string agentName);