docs: initialize go-live MVP mission with coordinator protocol

First dogfood of mosaic coord tooling on a real project.
Mission: 4 milestones from dashboard polish through deploy+smoke.
Scaffolded via `mosaic coord init`.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/scratchpads/mosaic-stack-go-live-mvp-20260222.md

@@ -0,0 +1,21 @@
+# Mission Scratchpad — Mosaic Stack Go-Live MVP
+
+> Append-only log. NEVER delete entries. NEVER overwrite sections.
+> This is the orchestrator's working memory across sessions.
+
+## Original Mission Prompt
+
+```
+(Paste the mission prompt here on first session)
+```
+
+## Planning Decisions
+
+## Session Log
+
+| Session | Date | Milestone | Tasks Done | Outcome |
+| ------- | ---- | --------- | ---------- | ------- |
+
+## Open Questions
+
+## Corrections