feat: add global styles and transitions for dark mode support

- Created style.css for base styles and color variables for light and dark themes.
- Added tailwind.css for Tailwind CSS integration and custom theme variables.
- Introduced transitions.css to manage global transitions and reduce motion preferences.
- Updated tsconfig.app.json to include path aliases for easier imports.
- Modified tsconfig.json to set baseUrl and paths for module resolution.
- Added typed-router.d.ts for auto-generated route types.
- Enhanced vite.config.ts with Vue Router plugin, Tailwind CSS integration, and server proxy settings.

backend/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "backend",
+  "name": "budget-manager-pwa-backend",
   "module": "index.ts",
   "type": "module",
   "private": true,
@@ -9,12 +9,14 @@
     "@types/jsonwebtoken": "^9.0.9",
     "@types/koa": "^2.15.0",
     "@types/koa-bodyparser": "^4.3.12",
-    "@types/koa-router": "^7.4.8"
+    "@types/koa-router": "^7.4.8",
+    "@types/koa__cors": "^5.0.0"
   },
   "peerDependencies": {
     "typescript": "^5"
   },
   "dependencies": {
+    "@koa/cors": "^5.0.0",
     "bcrypt": "^6.0.0",
     "jsonwebtoken": "^9.0.2",
     "koa": "^3.0.0",