build: optimize Dockerfiles for production and pin dependencies

Implement multi-stage build and static server for frontend
Run containers as non-root user and set production environment
Pin all package dependencies to exact versions

frontend/package.json

@@ -12,18 +12,18 @@
     "test": "vitest run"
   },
   "dependencies": {
-    "@iconify/vue": "^5.0.0",
-    "@vitejs/plugin-vue": "latest",
-    "vite": "latest",
-    "vue": "latest",
-    "vue-i18n": "^11.4.0",
-    "vue-router": "latest"
+    "@iconify/vue": "5.0.0",
+    "@vitejs/plugin-vue": "6.0.6",
+    "vite": "8.0.10",
+    "vue": "3.5.33",
+    "vue-i18n": "11.4.0",
+    "vue-router": "5.0.6"
   },
   "devDependencies": {
-    "@types/node": "latest",
-    "@vue/tsconfig": "latest",
-    "typescript": "latest",
-    "vitest": "latest",
-    "vue-tsc": "latest"
+    "@types/node": "25.6.0",
+    "@vue/tsconfig": "0.9.1",
+    "typescript": "6.0.3",
+    "vitest": "4.1.5",
+    "vue-tsc": "3.2.7"
   }
 }