Expose /status rate-limit percentages (Session, Week, Sonnet-only) to statusLine command

Problem

The /status slash command shows three rate-limit usage percentages (Current session, Current week all-models, Current week Sonnet-only) that are extremely useful for tracking subscription budget mid-session. However these values are only visible inside the /status dialog and are not accessible to a custom statusLine.command script.

What I tried

• claude --print "/status" → returns "/status isn't available in this environment"
• claude --print --output-format=json "/status" → same
• ccusage (community CLI) has no limits subcommand
• No file under ~/.claude/ (stats-cache.json, .claude.json, transcripts) contains the percentages — Anthropic's anthropic-ratelimit-* response headers are stripped before transcript persistence
• OAuth-token-based API probing felt out of scope (likely ToS-grey)

Proposal

Either:

1. Pass the three percentages as additional fields in the JSON the harness sends to the statusLine.command on every render, e.g.:

``json
{
"rate_limits": {
"session_used_pct": 25,
"week_all_used_pct": 13,
"week_sonnet_used_pct": 0,
"session_resets_at": "2026-05-04T22:19:00Z",
"week_resets_at": "2026-05-10T03:00:00Z"
}
}
``

1. Or expose /status as a programmatically callable endpoint via claude --print (currently it answers "isn't available in this environment")
2. Or write the values to a file under ~/.claude/ after each render so external scripts can read the latest cached state

Why

Right now I can show cwd, model, token-cost and context-% via ccusage statusline — but I cannot mirror the exact three numbers from /status. For people on Max plans who hit weekly Sonnet caps, surfacing this in the statusline (instead of having to type /status multiple times per session) would be a real-time-budget UX win.

Environment

• Claude Code 2.1.x
• macOS / VS Code extension
• claude_max plan, organizationRateLimitTier: default_claude_max_5x