Fix warnings and update tracability

src-tauri/src/session_poller/mod.rs

@@ -2,6 +2,8 @@
 //!
 //! Manages background polling of Jellyfin sessions with dynamic frequency adjustment
 //! based on playback mode and UI state. Eliminates duplicate pollers across browser tabs.
+//!
+//! TRACES: UR-010 | JA-021
 
 use log::{debug, info, warn};
 use std::sync::{Arc, Mutex, RwLock};