refactor: full-stack restructure with multi-tenancy, workspace management, and K8s diagnostics

- Add Workspace domain (entity, repository, service, handler, DTO)
- Add multi-tenant K8s client with tenant binding and quota management
- Add K8s diagnostics client (instance diagnostics)
- Add authorization middleware (authz package)
- Restructure frontend to feature-based architecture (features/)
- Add User Management page in configuration
- Add AccessDenied page and route guards
- Refactor shared components (form inputs, layout, UI)
- Update Tailwind config for new design system
- Add comprehensive documentation (docs/, tasks/, plans)
- Improve cluster service with better kubeconfig handling
- Add tests for crypto, config, helm client, tenant binding

frontend/package.json

@@ -18,7 +18,8 @@
     "react": "^19.1.1",
     "react-dom": "^19.1.1",
     "react-router-dom": "^7.9.4",
-    "reflect-metadata": "^0.2.2"
+    "reflect-metadata": "^0.2.2",
+    "yaml": "^2.8.4"
   },
   "devDependencies": {
     "@eslint/js": "^9.36.0",