fix: resolve TypeScript errors in vite.config.ts

- Install @types/node for node:path, node:process, node:url
- Import defineConfig from vitest/config for test config type
- Add types: ["node"] to tsconfig.json

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

tsconfig.json

@@ -12,6 +12,7 @@
     "module": "ESNext",
     "target": "ESNext",
     "isolatedModules": true,
+    "types": ["node"],
     "paths": {
       "$lib/*": ["./src/lib/*"]
     }