Add OpenClaw as an AI agent option

[mbot11]

Add OpenClaw as an AI agent option

Summary

Adds OpenClaw (formerly Clawdbot/Moltbot) to the AI
coding-agent roster on quattro, following the exact conventions of the
existing agents:

• lazy-loaded launcher via mise (agent_package="npm:openclaw")
• a row in Setup > Defaults > Agent with the standard checkmark guard
• an unattended launch mapping in omarchy-agent (openclaw tui, prompt
  seeded via --message)
• an agents-panel usage collector matching the packaged collector record
  contract (schemaVersion: 1), writing openclaw.json next to
  claude.json and codex.json

Why

OpenClaw is one of the most widely used agent harnesses, and its terminal UI
(openclaw tui) is a full agent surface with tool approvals. Users who run it
alongside Claude Code / Codex / OpenCode currently get no agents-panel usage
tracking and no default-agent option. This patch closes both gaps the same way
every other agent is wired.

Changes

1. bin/omarchy-default-agent — openclaw / open-claw case, usage strings
2. bin/omarchy-agent — launch case: openclaw tui (gateway-connected TUI),
   --message "$prompt" for prompt seeding
3. default/omarchy/omarchy-menu.jsonc — setup.default.agent.openclaw row
4. bin/omarchy-agent-usage-openclaw — new usage collector (same record
   contract as the packaged collectors; discovers sessions via
   openclaw sessions --json --all-agents and prompt counts from gateway
   audit events)

Notes for review

• OpenClaw is a gateway-first tool; openclaw tui talks to the local Gateway
  (loopback) and works headless, so the launch mapping needs no special flags.
• The usage collector shells out to the openclaw CLI rather than reading its
  state SQLite directly (the store uses the sqlite-vec extension), which
  also keeps it stable across OpenClaw schema changes.
• The collector only reports metadata (counts, model names, token totals) —
  no message content, credentials, or provider keys are read or written.

Testing

• bash -n on both modified scripts; JSONC parse on the modified menu
• openclaw tui launches against a running gateway and accepts --message
• collector verified against a live gateway: correct today/session/token
  aggregates, atomic write to ~/.local/state/omarchy/agents/usage/openclaw.json