feat: add server-sent events for logging and activity tracking

- Implemented a custom tracing layer (`AppLogLayer`) to capture log events and broadcast them to SSE clients.
- Created admin routes for streaming server logs and listing recent activity logs.
- Added an activity log repository interface and SQLite implementation for persisting activity events.
- Integrated activity logging into user authentication and channel CRUD operations.
- Developed frontend components for displaying server logs and activity logs in the admin panel.
- Enhanced the video player with a stats overlay for monitoring streaming metrics.

k-tv-backend/infra/src/lib.rs

@@ -18,6 +18,7 @@ pub mod db;
 pub mod factory;
 pub mod jellyfin;
 pub mod provider_registry;
+mod activity_log_repository;
 mod channel_repository;
 mod schedule_repository;
 mod user_repository;
@@ -29,6 +30,8 @@ pub mod local_files;
 pub use db::run_migrations;
 pub use provider_registry::ProviderRegistry;
 
+#[cfg(feature = "sqlite")]
+pub use activity_log_repository::SqliteActivityLogRepository;
 #[cfg(feature = "sqlite")]
 pub use user_repository::SqliteUserRepository;
 #[cfg(feature = "sqlite")]