Show 5-hour rate limit usage status in the status bar

Feature Request

Description

Add the ability to display the 5-hour rate limit / session usage quota in the Claude Code status bar (statusline).

Problem

Currently, there's no way to see how much of the 5-hour usage window you have remaining while working. Users only find out they're near the limit when they get a warning or hit it. This makes it hard to pace usage during long sessions.

Proposed Solution

Expose rate limit / quota data (e.g., messages remaining, time until reset, percentage of quota used) as fields available to the statusLine configuration in settings.json. This would allow users to see their 5-hour session limit status at a glance in the status bar.

Example display:

GammaEdge (main) | Claude Opus 4.6 | Quota: 62% remaining (resets in 3h 12m)

Current Limitation

The statusline JSON input currently includes context window tokens, model info, session ID, and workspace details — but does not include any rate limit or quota information. The 5-hour usage limit is tracked server-side and not exposed to the client.

Why This Matters

• Helps users pace their usage across the 5-hour window
• Prevents surprise rate limit hits during critical work
• Gives visibility into a metric that directly impacts workflow continuity