Rename CLUSTER-READY → K8S-CLUSTER (more direct)

Also added:
- DEVELOPMENT-WORKFLOW.md - Complete dev process documented
- Updated all references across documentation

Documentation is now centralized and direct.

Co-Authored-By: Claude Sonnet 4.5 (1M context) <noreply@anthropic.com>

k8s/backend/secrets.yaml

@@ -0,0 +1,9 @@
+apiVersion: v1
+data:
+  db-password: QWlXb3JrZXIyMDI2X1VzZXJQYXNzXCE=
+  gitea-token: MTU5YTVkZTJhMTZkMTVmMzNlMzg4YjU1YjEyNzZlNDMxZGJjYTNmMw==
+kind: Secret
+metadata:
+  creationTimestamp: null
+  name: backend-secrets
+  namespace: control-plane