Proposal: Response-header template for gstack

Hi Garry — Benito of RobotBird here, Claude Code user. Big fan of gstack.

Proposal: a response-header template for gstack, similar in spirit to agent-persona templates that exist for a few other Claude Code skills.

Proposed template:

```
+----------------------------------------------+
| gstack (🎯) | [active skill] | Step [x/y] |
| [current stage] | [topic] |
+----------------------------------------------+
```

Glyph 🎯 chosen for strategic targeting.

Active gstack skills it'd cover: `/plan-ceo-review`, `/plan-eng-review`, `/review`, `/ship`, `/retro`, `/qa`, `/browse`, `/office-hours`, `/design-consultation`, `/design-review`, `/document-release`, etc.

Optional + no urgency. Happy to draft a PR if you'd want one.

Thanks for considering.

— Benito of RobotBird (@AtelierBenito)