Expose effort level in statusLine JSON input

Feature Request

The statusLine command receives a JSON payload via stdin with model info, context window, cost, etc. However, the effort/reasoning level (set via /model) is not included.

Current JSON model object:

{
  "id": "claude-opus-4-6[1m]",
  "display_name": "Opus 4.6 (1M context)"
}

Requested addition:

{
  "id": "claude-opus-4-6[1m]",
  "display_name": "Opus 4.6 (1M context)",
  "effort": "max"
}

Why

Users who customize their statusLine want to see the current effort level at a glance without having to cycle through /model to check. This is especially useful when frequently switching between effort levels (min/low/medium/high/max).

Workaround

None - the effort is tracked at runtime but not passed to the statusLine command, so there's no way to display it currently.