Fix: Implement iframe-compatible authentication

src/lib/authStorage.ts

@@ -0,0 +1,58 @@
+/**
+ * Custom storage adapter for Supabase authentication that handles iframe localStorage restrictions.
+ * Falls back to sessionStorage or in-memory storage if localStorage is blocked.
+ */
+class AuthStorage {
+  private storage: Storage | null = null;
+  private memoryStorage: Map<string, string> = new Map();
+  private storageType: 'localStorage' | 'sessionStorage' | 'memory' = 'memory';
+
+  constructor() {
+    // Try localStorage first
+    try {
+      localStorage.setItem('__supabase_test__', 'test');
+      localStorage.removeItem('__supabase_test__');
+      this.storage = localStorage;
+      this.storageType = 'localStorage';
+      console.log('[AuthStorage] Using localStorage');
+    } catch {
+      // Try sessionStorage as fallback
+      try {
+        sessionStorage.setItem('__supabase_test__', 'test');
+        sessionStorage.removeItem('__supabase_test__');
+        this.storage = sessionStorage;
+        this.storageType = 'sessionStorage';
+        console.log('[AuthStorage] localStorage blocked, using sessionStorage');
+      } catch {
+        // Use in-memory storage as last resort
+        this.storageType = 'memory';
+        console.log('[AuthStorage] Both localStorage and sessionStorage blocked, using in-memory storage');
+      }
+    }
+  }
+
+  getItem(key: string): string | null {
+    if (this.storage) {
+      return this.storage.getItem(key);
+    }
+    return this.memoryStorage.get(key) || null;
+  }
+
+  setItem(key: string, value: string): void {
+    if (this.storage) {
+      this.storage.setItem(key, value);
+    } else {
+      this.memoryStorage.set(key, value);
+    }
+  }
+
+  removeItem(key: string): void {
+    if (this.storage) {
+      this.storage.removeItem(key);
+    } else {
+      this.memoryStorage.delete(key);
+    }
+  }
+}
+
+export const authStorage = new AuthStorage();