Summary

This PR adds two lightweight usage indicators to the status bar to make session monitoring easier without opening the stats view.

• add a context gauge for the active session based on the latest assistant usage entry found in the session .jsonl
• add a 5h quota gauge using the existing usage data, with a shortcut to the Stats tab
• expose the new session token IPC bridge from Electron main to the renderer
• style both gauges and integrate them into the existing status bar layout
• ignore local JetBrains .idea metadata files

Why

The goal is to surface the most useful runtime limits directly in the main UI:

• current context consumption for the selected session
• current 5h quota usage at a glance
  This reduces friction when deciding whether to continue in the same session or switch context.

Notes

• the context gauge refreshes when a session becomes active and when Claude finishes responding
• the quota gauge refreshes automatically every 5 minutes
• both gauges stay hidden when no data is available

Testing

• UI change only
• not manually tested in this branch