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>

vite.config.ts

@@ -1,7 +1,7 @@
 import path from 'node:path';
 import process from 'node:process';
 import { fileURLToPath } from 'node:url';
-import { defineConfig } from 'vite';
+import { defineConfig } from 'vitest/config';
 import { svelte } from '@sveltejs/vite-plugin-svelte';
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));