Ports the OpenCode /start-work flow onto Codex as a discoverable skill.
The skill drives plan selection, Boulder state with codex:<session_id>
prefixed ids, worktree binding, parallel spawn_agent sub-tasks with
6-section prompts, 4-channel Manual-QA evidence (HTTP / tmux / browser /
computer use), ledger append at .omo/start-work/ledger.jsonl, and a
4-phase verification gate. Pairs with the start-work-continuation Codex
Stop / SubagentStop hook component that re-injects continuation while
boulder.json shows incomplete work for the active codex: session.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>