Previous commit had the command typed as Result<tauri::ipc::Response,
String>. Turns out that forces Tauri to JSON-serialise the variant
wrapper around the Response body — the frontend gets a JSON object
instead of the raw ArrayBuffer, the runtime check for byteLength fails,
and every thumbnail comes back as null.
Changed the return type to `tauri::ipc::Response` directly. Bad source
ids and capture failures now funnel into an empty byte buffer; the JS
side still detects "no thumbnail" via `byteLength === 0` so the
contract stays the same.
Frontend also widens the invoke-result typing to ArrayBuffer |
Uint8Array | number[] so an older WebView2 that happens to deserialise
as an array still works, and normalises into a plain ArrayBuffer
before constructing the Blob to sidestep a TS SharedArrayBuffer
incompatibility.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
