Feature: Include weekly usage/limit data in status line JSON

Feature Request

Is your feature request related to a problem?

The status line is highly customizable and great for at-a-glance session info, but there's no way to display account-level weekly usage against plan limits. The JSON data available to status line scripts only includes session-level metrics (tokens, cost, context window usage) — not account-level usage or remaining capacity.

As a heavy CLI user, I'd like to see how much of my weekly quota I've consumed without leaving the terminal or opening the web dashboard.

Proposed Solution

Include account-level usage data in the JSON payload passed to status line scripts. Something like:

{
  "weekly_usage": {
    "used": 1234567,
    "limit": 5000000,
    "percentage": 24.7,
    "reset_date": "2026-02-22T00:00:00Z"
  }
}

This would allow status line scripts to display usage info like:

opus-4-6 | 24.7% weekly (1.2M/5M) | ctx: 45% | $2.34

Alternatives Considered

• External API call in status line script: Works but requires separate authentication, caching to avoid latency on the 300ms refresh cycle, and is fragile.
• SessionStart hook: Can warn at session start but doesn't provide continuous visibility.
• Web dashboard: Requires context-switching out of the terminal.

Additional Context

The status line already has the infrastructure for this — it just needs the data. Since the CLI already knows the authenticated user and plan, surfacing the usage/limit info in the status line JSON would be a natural extension.