feat: implement unified AuthForm component for login and signup pages

apps/web/package.json

@@ -2,7 +2,7 @@
   "name": "next-template",
   "version": "0.1.0",
   "private": true,
-  "packageManager": "bun@1.2.2",  
+  "packageManager": "bun@1.2.2",
   "scripts": {
     "dev": "next dev --turbopack",
     "build": "next build",
@@ -51,6 +51,7 @@
     "tailwind-merge": "^2.5.5",
     "tailwindcss-animate": "^1.0.7",
     "vaul": "^1.1.1",
+    "zod": "^3.25.67",
     "zustand": "^5.0.2"
   },
   "devDependencies": {