Expose session/plan usage data to status line

Feature request

The status line JSON payload currently includes context window usage, model info, and workspace details — but no information about session or plan-level usage (e.g. remaining messages, tokens used vs. quota, rate limit status).

It would be great to include session/plan usage data in the status line input so users can build visual indicators showing how much of their Claude allocation remains. This is one of the most natural things to want on a status bar, and there's currently no way to access it from the status line script.

Suggested additions to the status line JSON

Any of the following would be useful:

• Messages or tokens used / remaining in the current session or billing period
• Rate limit status (requests remaining, reset time)
• Plan tier info

Use case

Building a usage bar in the status line so you can see at a glance how much Claude you have left before hitting a limit, without needing to check the web dashboard.