feat(omo-codex): add start-work skill markdown

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>

packages/omo-codex/plugin/test/sync-skills.test.mjs

@@ -12,11 +12,15 @@ const expectedSkills = [
 	"debugging",
 	"frontend-ui-ux",
 	"lsp",
+	"metis",
+	"momus",
+	"planing-prometheustic",
 	"programming",
 	"refactor",
 	"remove-ai-slops",
 	"review-work",
 	"rules",
+	"start-work",
 	"ultragoal",
 ];