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/api/Cargo.toml

@@ -56,6 +56,8 @@ uuid = { version = "1.19.0", features = ["v4", "serde"] }
 
 # Logging
 tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter", "fmt"] }
+tokio-stream = { version = "0.1", features = ["sync"] }
 
 reqwest = { version = "0.12", features = ["json"] }
 handlebars = "6"