Cannot paste in empty markdown file

* from the Files tree
* create new file.md
* try to paste
* :bug: no effect

```
Version: 1.127.0-insider
Commit: 3cf8af2ee6b3acc2ea190f0e6fbf3072b680511d
Date: 2026-06-25T09:50:18+02:00
Electron: 42.2.0
ElectronBuildId: 14159160
Chromium: 148.0.7778.97
Node.js: 24.15.0
V8: 14.8.178.14-electron.0
OS: Darwin arm64 25.5.0
```