Add Hermes usage collector for the agents panel

[mbot11]

Add Hermes usage collector for the agents panel

Summary

Adds an agents-panel usage collector for Hermes Agent, following the same record contract as the packaged claude/codex/fireworks collectors (schemaVersion: 1), so Hermes sessions show up in the agents panel alongside the built-in agents.

Why

omarchy-agent-usage-update discovers bin/omarchy-agent-usage-* collectors, and Hermes currently has none — users who work in Hermes get no usage tracking in the panel even though Hermes sessions are first-class coding-agent sessions. This fills that gap the same way every packaged collector is wired; no other changes are needed for the panel to pick it up.

Changes

1. bin/omarchy-agent-usage-hermes — new collector:
   • reads local session stats from Hermes' state store (~/.hermes/state.db: sessions, messages, per-model token usage)
   • emits the standard display-ready JSON record (today/recent-day prompt counts, active days, per-model token breakdown, ready/status fields)
   • --write mode updates the record file atomically so a user timer (or this script being adopted into omarchy-agent-usage-update) can keep the panel fresh
   • chat sessions that arrived over messaging gateways count too — Hermes treats them as first-class sessions

Notes for review

• The collector only reads metadata (counts, model names, token totals) — no message content, credentials, or provider keys are read or written.
• Read-only SQLite access (mode=ro), so it never contends with a running Hermes gateway.

Testing

• python3 -m py_compile clean
• Verified against a live Hermes install: record matches the panel contract, per-day counts and model token totals agree with the underlying database, atomic --write lands hermes.json in ~/.local/state/omarchy/agents/usage/