feat: complete E2E deployment flow with storage layered config and values template versioning

- Instance deployment: charts browser, deploy modal, instances list
- Values Template version management (create/history/rollback)
- Storage layered config (cluster > workspace > shared priority)
- Cluster credential decryptIfNeeded for mixed encrypted/plaintext kubeconfig
- YAML syntax validation (client-side + server-side warning)
- Frontend: charts, instances, storage, templates, admin pages
- Backend: storage service, instance service, cluster service, helm client
- Multi-Tenant Kubeconfig.md: added by user

.gitignore

@@ -36,6 +36,9 @@ build/
 backend/bin/
 frontend/dist/
 
+# Compiled binaries
+backend/ocdp-backend
+
 # Logs
 *.log
 logs/
@@ -61,3 +64,17 @@ tmp/
 temp/
 *.tmp
 
+# Next.js stale build caches
+frontend/.next.stale*/
+
+# Debug/temp scripts
+debug_*.py
+test_*.py
+
+# Kubeconfig (contains sensitive credentials)
+*.kubeconfig
+kubeconfig
+
+# AI model output / context storage
+.claude/
+