What happened?

In the desktop app, pressing Delete / Backspace outside an editable field can trigger browser-style back navigation and send the user to the previous session route.

Steps to reproduce

1. Open the desktop app and navigate between sessions so the webview has history.
2. Focus a non-editable area.
3. Press Delete / Backspace on macOS.

Expected behavior

Delete / Backspace should only affect editable controls or do nothing in non-editable areas. It should not navigate session history.

Additional context

The app intentionally supports history navigation via common.goBack / common.goForward, and previous-session navigation is separately bound to Option+ArrowUp / Option+ArrowDown. This makes the plain Delete / Backspace behavior look like accidental webview fallback rather than an intentional keybind.

I also checked the pinned keybind docs/context in #4997 and https://opencode.ai/docs/keybinds. I did not find this behavior documented as an intended keybind, which further suggests this is accidental webview/browser fallback rather than expected shortcut behavior.