- Introduce interfaces for all major services (JWT, PostAI, Comment, Message, Notification, QRCodeLogin, Upload, Vote, etc.) to support dependency inversion.
- Move query parameters from `internal/dto` to a new `internal/query` package to separate request payloads from data transfer objects.
- Refactor `internal/router` to use embedded `RouterDeps` for cleaner dependency management.
- Decouple handlers from repositories by injecting services instead of direct repository access, ensuring proper layering.
- Improve database initialization by moving it from `internal/model` to `internal/database`.
- Optimize message decryption by implementing a more efficient `BatchDecrypt` method in `MessageEncryptor` using a worker pool.
- Enhance error handling and security by implementing fail-fast checks for encryption key length during startup.
- Clean up unused code, including the `avatar` package and several unused DTOs.
Add support for fetching and synchronizing empty classroom data. This includes new protobuf definitions for task payloads and results, database models, repository, service, and HTTP handlers.
- Add `TASK_TYPE_GET_EMPTY_CLASSROOM` to `TaskType` enum
- Implement `EmptyClassroom` model and auto-migration
- Add `EmptyClassroomHandler` with `GET` and `POST /sync` routes
- Implement `EmptyClassroomSyncService` and `EmptyClassroomRepository`
- Update dependency injection with wire sets
