PWA on Android crashes when attaching video/audio files via file picker (JPEG/PDF work fine) #3521

Environment

· Nextcloud version: 34.0.1
· Nextcloud Forms version: 5.3.4
· Client: Android PWA (installed via "Add to Home Screen" from Google Chrome)
· Android version: 12 (MIUI 14)
· Android System WebView version: 150.0.7871.46
· Device: XIAOMI Poco x3 nfc

Steps to reproduce

1. Open a form with file upload in the PWA
2. Tap upload and select a video file (.mp4)
3. Test with files of different sizes

Actual behavior

· 2.06 MB video → uploaded successfully
· 2.42 MB video → crash / error
· JPEG images up to 8 MB → uploaded successfully regardless of size
· The crash happens immediately on file selection, before network upload

Root cause (assumed)
Android WebView's file picker has a fixed IPC buffer (~2 MiB) when transferring selected files to the PWA. For video/audio, WebView likely tries to read metadata or generate a thumbnail within this limited buffer. Images are handled differently by the system media provider, bypassing this limit. This is a known class of WebView limitation, and a workaround on the Forms side is needed (e.g., chunked file reading).