feat(node): Implements node group selection functionality

- Introduces the Group entity and groupRepository
- Adds a new database utility function, getDatabase, to centrally retrieve database instances
- Removes the loading state and skeleton screen logic from nodeList to simplify the page structure
- Updates dependencies and adds the zod library for data validation

package.json

@@ -17,7 +17,8 @@
     "@tauri-apps/plugin-sql": "~2",
     "vue": "^3.5.21",
     "vue-router": "^4.5.1",
-    "vuetify": "^3.10.1"
+    "vuetify": "^3.10.1",
+    "zod": "^4.1.12"
   },
   "devDependencies": {
     "@tauri-apps/cli": "^2",