Switch Drive fetch to JSONP to bypass CORS restrictions

Apps Script redirects cause CORS proxies to timeout. JSONP via
dynamic script tag injection bypasses CORS entirely and works
reliably with Google Apps Script web app endpoints.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: creazyfrog

src/hooks/useGoogleDriveFolder.ts

@@ -34,20 +34,31 @@ interface DriveFile {
   createdTime?: string
 }
 
+function fetchViaJSONP(url: string): Promise<{ files: DriveFile[] }> {
+  return new Promise((resolve, reject) => {
+    const cbName = `_driveCallback_${Date.now()}`
+    const script = document.createElement('script')
+    ;(window as Record<string, unknown>)[cbName] = (data: { files: DriveFile[] }) => {
+      delete (window as Record<string, unknown>)[cbName]
+      document.head.removeChild(script)
+      resolve(data)
+    }
+    script.src = `${url}&callback=${cbName}`
+    script.onerror = () => {
+      delete (window as Record<string, unknown>)[cbName]
+      document.head.removeChild(script)
+      reject(new Error('JSONP failed'))
+    }
+    document.head.appendChild(script)
+  })
+}
+
 let cache: Project[] | null = null
 
 export async function fetchDriveVideos(): Promise<Project[]> {
   if (cache !== null) return cache
 
-  // Route through CORS proxy since Apps Script doesn't send CORS headers
-  const proxyUrl = `https://api.allorigins.win/get?url=${encodeURIComponent(APPS_SCRIPT_URL)}`
-  const res = await fetch(proxyUrl)
-  if (!res.ok) return []
-
-  const { contents } = await res.json()
-  if (!contents) return []
-
-  const { files } = JSON.parse(contents)
+  const { files } = await fetchViaJSONP(APPS_SCRIPT_URL)
   if (!Array.isArray(files)) return []
 
   const projects: Project[] = files.flatMap((file: DriveFile) => {