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.

middleware/auth.global.ts

@@ -0,0 +1,44 @@
+import { useAuth0 } from "@auth0/auth0-vue";
+import { watch } from "vue";
+import { abortNavigation, defineNuxtRouteMiddleware } from "nuxt/app";
+
+const waitUntilLoaded = async (isLoading: { value: boolean }) => {
+  if (!isLoading.value) {
+    return;
+  }
+
+  await new Promise<void>((resolve) => {
+    const stop = watch(
+      () => isLoading.value,
+      (value) => {
+        if (!value) {
+          stop();
+          resolve();
+        }
+      }
+    );
+  });
+};
+
+export default defineNuxtRouteMiddleware(async (to) => {
+  if (process.server) {
+    return;
+  }
+
+  if (to.path.startsWith("/auth/callback")) {
+    return;
+  }
+
+  const auth0 = useAuth0();
+  await waitUntilLoaded(auth0.isLoading);
+
+  if (auth0.isAuthenticated.value) {
+    return;
+  }
+
+  await auth0.loginWithRedirect({
+    appState: { target: to.fullPath },
+  });
+
+  return abortNavigation();
+});

middleware/auth.ts

@@ -0,0 +1,44 @@
+import { useAuth0 } from "@auth0/auth0-vue";
+import { watch } from "vue";
+import { abortNavigation } from "#app";
+
+const waitUntilLoaded = async (isLoading: { value: boolean }) => {
+  if (!isLoading.value) {
+    return;
+  }
+
+  await new Promise<void>((resolve) => {
+    const stop = watch(
+      () => isLoading.value,
+      (value) => {
+        if (!value) {
+          stop();
+          resolve();
+        }
+      }
+    );
+  });
+};
+
+export default defineNuxtRouteMiddleware(async (to) => {
+  if (import.meta.server) {
+    return;
+  }
+
+  if (to.path.startsWith("/auth/callback")) {
+    return;
+  }
+
+  const auth0 = useAuth0();
+  await waitUntilLoaded(auth0.isLoading);
+
+  if (auth0.isAuthenticated.value) {
+    return;
+  }
+
+  await auth0.loginWithRedirect({
+    appState: { target: to.fullPath },
+  });
+
+  return abortNavigation();
+});