K8s Migration Phase 1: Infrastructure Setup (#29)

## Summary
- Split k8s migration plan into phases folder for easier navigation
- Added `tag:k8s` to Pulumi ACLs for Kubernetes workloads
- Phase 1 work in progress

## Phase 1 Goals
- Tailscale Kubernetes Operator
- CloudNativePG Operator
- PostgreSQL cluster for future app migrations

## Deployment and Testing
- [ ] Review Phase 1 plan
- [ ] `mise run tailnet-preview` to verify ACL changes
- [ ] `mise run tailnet-up` to apply ACL changes
- [ ] Create Tailscale OAuth client (manual)
- [ ] Deploy operators and PostgreSQL cluster

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Reviewed-on: https://forge.tail8d86e.ts.net/eblume/blumeops/pulls/29

.yamllint.yaml

@@ -27,3 +27,5 @@ rules:
 ignore:
   - .venv/
   - pulumi/.venv/
+  # Third-party k8s manifest with non-standard formatting
+  - argocd/manifests/tailscale-operator/operator.yaml