Android: downloadFile requests storage permission for app-private file paths

[mustafa0x]

Description

On Android < 30, FileTransfer.downloadFile() appears to require public storage permission even when the destination is an app-private file:// path under the app data directory.

In our Capacitor app, downloading a ~21 MB SQLite metadata snapshot to an app-private path failed almost immediately on Android 9/10 with:

Error during file transfer

The same download succeeds when using deprecated Filesystem.downloadFile() with directory: Directory.Data, which only checks storage permission for public directories.

Reproduction shape

const path = `tmp/data.sqlite`
await Filesystem.mkdir({ path: `tmp`, directory: Directory.Data, recursive: true })
const { uri } = await Filesystem.getUri({ path, directory: Directory.Data })

// Fails quickly on Android < 30 due to storage permission path
await FileTransfer.downloadFile({ url, path: uri })

// Works; writes to app-private storage
await Filesystem.downloadFile({
  url,
  path,
  directory: Directory.Data,
  recursive: true,
})

Expected behavior

FileTransfer.downloadFile() should not require public/external storage permission when the destination is app-private storage, or it should provide an option/API shape equivalent to Filesystem.downloadFile({ directory: Directory.Data }).

Versions

• @capacitor/core: ^8.3.1
• @capacitor/file-transfer: ^2.0.4
• @capacitor/filesystem: ^8.1.2
• Observed on Android 9/10; API 28 repro confirmed.