docs(vibe): add new-tool and new-app runbooks (grounded in real PRs)

Two agent-oriented runbooks under vibe/runbooks/ with [AGENT]/[HUMAN] step
markers, grounded in real diffs:

- new-tool.md : add a platform component to the tools repo so ArgoCD deploys it
  into the tools namespace (wrapper Chart.yaml + the tool library + a row in
  chart/values.yaml; optional iac/ for secrets). Mirrors the prometheus/crowdsec
  additions.
- new-app.md  : stand up a brand-new application across THREE repos (app +
  factory + tools) with the strict ordering dependency and the TERRAFORM_SSH_KEY
  pitfall. Phase-by-phase mapped to the dance-lessons-coach onboarding PRs
  (#89/#97/#98/#99/#100), factory #1/#2, tools #1; the FR doc/runbooks/new-web-app
  is linked as the detailed companion.

2 mermaid diagrams MCP-validated; zero dead links across the vibe tree.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

vibe/runbooks/README.md

@@ -45,6 +45,8 @@ flowchart LR
 | Runbook | Summary | Status |
 |---|---|---|
 | [_template](_template.md) | Skeleton for new agent-oriented runbooks (`[AGENT]`/`[HUMAN]` markers, copy-paste commands, verification + rollback) | ✅ Active |
+| [Set up a new tool](new-tool.md) | Add a platform component to the `tools` repo so ArgoCD deploys it | ✅ |
+| [Set up a new app](new-app.md) | Stand up a brand-new application — its own repo, chart, CI/CD with IaC, and database access, across the app + factory + tools repos | ✅ |
 
 > [!NOTE]
 > The first **concrete** runbook — a local sandbox game-day for the safe prod-like environment — ships with **PRD Phase 1** ([safe-prod-like-environment PRD](../PRD/safe-prod-like-environment/README.md)). Until then this folder holds the conventions and the template only.