refactor(skills): cleanup dead code + full workflow A→B→C→D integration

Cleanup:
- Remove unused validate_yaml() helper from lib.sh
- Remove USER_MANUAL.html + mqtt-broker-setup.html (no refs found)

Workflow A (create_session ↔ delegate-job):
- Add --submit-job <prompt> option to create_session.sh
- Auto-register session in delegate-job registry, store delegate_job_id in YAML

Workflow B (push-based monitor):
- Migrate reconcile.sh to MQTT subscriber mode (polling fallback preserved)

Workflow C (unified status):
- status.sh now shows session + delegate-job state in single column

Workflow D (audit log + perms):
- JSON job files chmod 600
- create/delete/resume now publish lifecycle events to delegate-job

skills/multi-agent-create/SKILL.md

@@ -76,6 +76,11 @@ To prevent this, you can run this skill inside an **isolated tmux server** using
    ```bash
    bash scripts/create_session.sh --workspace /path/to/project --agent claude --tmux-server multi-agent-canary
    ```
+3. **Submit Job Integration**:
+   You can automatically register a delegated job with a prompt when creating a session:
+   ```bash
+   bash scripts/create_session.sh --workspace /path/to/project --agent claude --submit-job "Task prompt here"
+   ```
 
 ### Recommended Alias
 You can set an alias in your shell to easily query sessions on the isolated server: