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.

nuxt.config.ts

@@ -5,6 +5,30 @@ export default defineNuxtConfig({
   compatibilityDate: "2025-07-15",
   devtools: { enabled: true },
   css: ["./app/assets/css/main.css"],
+  runtimeConfig: {
+    auth0: {
+      clientSecret: process.env.AUTH0_CLIENT_SECRET,
+    },
+    supabase: {
+      serviceRoleKey: process.env.SUPABASE_SERVICE_ROLE_KEY,
+    },
+    public: {
+      auth0: {
+        domain: process.env.AUTH0_DOMAIN,
+        clientId: process.env.AUTH0_CLIENT_ID,
+        audience: process.env.AUTH0_AUDIENCE,
+        scope: process.env.AUTH0_SCOPE ?? "openid profile email",
+        baseUrl: process.env.AUTH0_BASE_URL ?? "http://localhost:3000",
+        redirectUri:
+          process.env.AUTH0_REDIRECT_URI ?? "http://localhost:3000/auth/callback",
+      },
+      supabase: {
+        url: process.env.SUPABASE_URL,
+        anonKey: process.env.SUPABASE_ANON_KEY,
+        storageBucket: process.env.SUPABASE_STORAGE_BUCKET ?? "designs",
+      },
+    },
+  },
   vite: {
     plugins: [tailwindcss()],
   },