Feature Request: Expose account-wide usage data to status line

Problem

The status line currently only has access to session-local data (context window usage, session cost), but not the account-wide usage percentages that are shown in /usage.

When running /usage, users can see:

• Current session: 23% used (resets daily)
• Current week (all models): 12% used (resets weekly)

However, these percentages are not available in the status line JSON context, making it impossible to display account-wide usage limits in the status line.

Current Behavior

The status line JSON only exposes:

{
  "context_window": {
    "used_percentage": 14  // This is session-local context, not account usage
  },
  "cost": {
    "total_cost_usd": 0.66  // Session cost only
  }
}

This causes confusion because users see different percentages in different places:

• Status line shows context window usage (e.g., 14%)
• /usage shows actual account limits (e.g., 23% session, 12% weekly)
• Different machines show different status line percentages for the same account

Requested Feature

Expose account-wide usage data to the status line JSON so users can configure their status line to show actual account usage limits instead of (or in addition to) session-local metrics.

Proposed JSON fields:

{
  "account_usage": {
    "session": {
      "used_percentage": 23,
      "resets_at": "2026-02-13T18:00:00+11:00"
    },
    "weekly": {
      "used_percentage": 12,
      "resets_at": "2026-02-18T19:59:00+11:00"
    },
    "extra_usage": {
      "enabled": false,
      "available_usd": 50
    }
  }
}

Use Case

With this data available, users could configure their status line to show:

✨ main │ Sonnet 4.5 │ session: 23% │ week: 12%

This would:

• Be consistent across all machines (account-wide, not session-local)
• Help users track their actual usage toward their limits
• Match the data shown in /usage
• Reduce the need to constantly run /usage to check account status

Benefits

1. Consistency: Same usage percentage across all machines
2. Clarity: Clear distinction between context window usage and account usage limits
3. Convenience: At-a-glance view of account status without running /usage
4. Customization: Users can choose what matters most to them (session vs weekly vs cost)

Workaround

Currently, users must:

1. Periodically run /usage to check account-wide limits
2. Status line can only show session cost as a proxy for usage