[FEATURE] Expose rate limit/session usage data to statusLine configuration

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The statusLine configuration currently receives context window usage data (context_window.used_percentage) but does not have access to the rate limit/session usage percentage shown in /status under the "Usage" tab. This is the hourly quota that shows "Current session: X% used" and resets periodically.

Users who want to monitor their API usage quota in the statusLine cannot do so because this data is not exposed in the JSON input passed to statusLine commands.

Proposed Solution

Add rate limit usage data to the statusLine JSON input. Suggested fields:

• rate_limit.session_used_percentage - Current session usage (0-100)
• rate_limit.session_reset_time - When the session quota resets
• rate_limit.weekly_used_percentage - Current week usage (0-100)
• rate_limit.weekly_reset_time - When the weekly quota resets

Alternative Solutions

Currently there's no workaround. Users must run /status manually to check their rate limit usage, which interrupts workflow.

Priority

Low - Nice to have

Feature Category

CLI commands and flags

Use Case Example

1. User configures a custom statusLine to display system info
2. User wants to see their remaining API quota at a glance
3. With this feature, user could add rate_limit.session_used_percentage to their statusLine
4. User can monitor quota without interrupting their workflow with /status

Additional Context

The context window percentage is already available via context_window.used_percentage, so the infrastructure for exposing percentage data to statusLine already exists. Rate limit data is displayed in /status so it's already being tracked internally.