feat: add design persistence functionality with Auth0 and Supabase integration

- Implemented `useDesignPersistence` composable for managing design records.
- Enhanced `useSlipmatDesigner` to support loading designs from JSON.
- Created global authentication middleware for route protection.
- Added Supabase client plugin for database interactions.
- Developed API endpoints for fetching, saving, and retrieving designs.
- Introduced utility functions for Auth0 token verification and Supabase client retrieval.
- Updated Nuxt configuration to include Auth0 and Supabase environment variables.
- Added necessary dependencies for Auth0 and Supabase.
- Enhanced TypeScript configuration for improved type support.

package.json

@@ -10,11 +10,18 @@
     "postinstall": "nuxt prepare"
   },
   "dependencies": {
+    "@auth0/auth0-vue": "^2.4.0",
     "@tailwindcss/vite": "^4.1.16",
+    "@supabase/supabase-js": "^2.48.0",
     "fabric": "^6.0.2",
+    "jose": "^5.9.6",
     "nuxt": "^4.2.0",
+    "zod": "^3.23.8",
     "tailwindcss": "^4.1.16",
     "vue": "^3.5.22",
     "vue-router": "^4.6.3"
+  },
+  "devDependencies": {
+    "@types/node": "^22.10.1"
   }
 }