Summary

Adds an on_status_bar_render plugin hook that lets plugins contribute extra text fragments to the CLI status bar, without requiring patches to cli.py.

Closes #8642.

Changes

hermes_cli/plugins.py

• Add "on_status_bar_render" to VALID_HOOKS

cli.py

• Invoke on_status_bar_render hook in both code paths of _build_status_bar_text():
  • Medium width (if width < 76): separator " · ", parts.append()
  • Full width: separator " │ ", parts.insert(-1, extra) before duration

Each callback receives a snapshot dict and may return a string to append, or None to contribute nothing. The hook is wrapped in try/except so a misbehaving plugin cannot break the status bar.

Snapshot dict

Plugins receive:

{
    "model_short": str,
    "model_full": str,
    "context_percent": int,
    "context_tokens": int,
    "context_length": int,
    "duration": str,
    "session_id": str,
    "session_title": str,
    "active_background_tasks": int,
    "active_background_processes": int,
    "compressions": int,
    "prompt_elapsed": float or None,
}

Use cases

With this hook, plugins can cleanly add:

• Quota/rate-limit status (Claude, Codex)
• Session title
• Active vision model indicator
• Cron job count
• Git dirty indicator
• Custom cost/usage tracking

Backwards compatibility

No breaking changes. Plugins that don't register this hook see no difference. The hook is purely additive.

Tested

• Plugin loads and hook is called on every status bar redraw
• Both width paths correctly display plugin output
• Hook failure does not break the status bar
• Hook works in idempotent re-application (survives hermes update)