Status line: expose monthly spend without requiring manual browser cookie extraction

Summary

Showing monthly spend in the Claude Code status line has no supported path today:

1. No spend data in the status line JSON — the payload includes model and context_window but not spend
2. No supported API for monthly spend — the only known endpoint requires a browser sessionKey cookie, which must be manually extracted from DevTools and re-extracted whenever it rotates

Requested changes (either would help, both would be ideal)

• Option A: Add spend (used/limit, monthly) to the status line JSON payload
• Option B: Document and stabilize a spend API endpoint that accepts an Anthropic API key, or expose claude spend as a CLI subcommand

For reference, the endpoint currently used via browser cookie workarounds is: GET https://claude.ai/api/organizations/{org_id}/overage_spend_limit?account_uuid={account_uuid}

Why this matters

Cost visibility at a glance — without leaving the terminal — is genuinely useful, especially in team environments where spend is shared. The token/model/context fields in the status line JSON are already great; spend is the missing piece.