feat(client): Enhance Log Viewer with Categories, Filtering, and Per-Session Tracing

[rcyw]

Summary

This PR significantly enhances the debugging and observability capabilities of the Deck client by introducing several new features to the logging system and the Log Viewer UI.

Key Changes

• ✨ Log Viewer Filtering:

  • Logs are now categorized as API, SSE, Error, or System.
  • The Log Viewer now has a filter bar, allowing developers to easily isolate specific types of events, which is especially useful for noisy applications.

• 🗂️ Per-Session SSE Tracing:

  • To simplify debugging individual user flows, SSE traces are no longer written to a single monolithic file.
  • They are now stored in a sessions directory, with one .jsonl file per session_id.
  • Includes an automatic cleanup mechanism to evict old log files based on age and total directory size, preventing uncontrolled disk usage.

• 🌉 Frontend Log Bridge:

  • A new Tauri command (log_frontend_message) has been added.
  • console.error and console.warn are now automatically forwarded to the Rust backend and captured in the main deck.log. This allows us to capture critical frontend errors that might otherwise be lost in production desktop builds.

How to Test

1. Run the client application.
2. Open the debug/log viewer.
3. Observe the new category filter buttons (API, SSE, Error, System).
4. Click the filters to verify that the log entries are correctly shown or hidden.
5. Perform some actions (e.g., send a message) and verify new log entries appear under the correct categories.
6. Check your app's log directory (<App Log Dir>/sessions/) and confirm that .jsonl files are being created for your sessions.