Add network map UX and theme support.

Introduce network map view/components with filtering and positioning, expand contacts/map backend fields and migrations, and add a persistent light/dark theme toggle with graph label color updates for readability.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/package.json

@@ -5,7 +5,9 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run",
+    "test:watch": "vitest"
   },
   "dependencies": {
     "vue": "^3.4.0",
@@ -16,7 +18,10 @@
     "vis-data": "^7.1.9"
   },
   "devDependencies": {
+    "@vue/test-utils": "^2.4.6",
     "@vitejs/plugin-vue": "^5.0.3",
-    "vite": "^5.1.0"
+    "jsdom": "^25.0.1",
+    "vite": "^5.1.0",
+    "vitest": "^2.1.9"
   }
 }