"Delete Proton files" should require confirmation

[missionfloyd]

Your system information

• Steam client version (build number or date): 1671675017
• Distribution (e.g. Ubuntu): SteamOS 3.4.4 build 20221228.1
• Opted into Steam client beta?: n
• Have you checked for system updates?: y

Please describe your issue in as much detail as possible:

This option should prompt for confirmation when selected, warning the user that it may delete saves. Most users coming from Windows aren't going to know what "Proton files" refers to and can end up losing their saves if they click it.

Alternatively, only show the "Developer" submenu if Developer Mode is enabled.

Steps for reproducing this issue:

1. Highlight a game and press ☰.
2. Open "Developer" submenu.
3. Click "Delete Proton files". The game's folder in ~/.local/share/steam/steamapps/compatdata is immediately deleted with no warning or confirmation.

[sibiryoff]

Strongly agree on that.

[Plotist]

Absolutely agree to that. I have just done that myself and lost 5 hours of progress. I would love to see a warning about save data as well.

[shmabler]

There should be a warning which explains this will delete save files, and anything else it does and ask for confirmation. Additionally, this option is not available on the desktop interface, so there should be interface consistency. Also, consider if this should be listed under "Developer" or another title depending on exactly what this feature does.