windowFrame: 'native' has no effect on Linux (Cinnamon)

Environment

• Hyper: v3.4.1 (deb)
• OS: Linux Mint 22.3, Cinnamon 6.6.7
• Window manager: Muffin (Cinnamon)

Issue

Setting windowFrame: 'native' in ~/.hyper.js config has no effect on Linux with Cinnamon desktop. Hyper still renders its custom titlebar with no maximize button.

The custom titlebar lacks a maximize button on Linux (only close and minimize are shown). There is no way to use system window decorations (server-side decorations) instead of Hyper's custom CSD.

Expected

windowFrame: 'native' should make Hyper use the system window manager decorations (including maximize, minimize, close buttons matching the system theme).

Screenshots

Screenshot showing custom titlebar without maximize button.

Additional context

The showWindowControls option only controls custom minimize/maximize/close drawn by Hyper itself, but doesn't switch to native system decorations.

Start by locating the handling of windowFrame and showWindowControls from ~/.hyper.js, then trace the Linux window-decoration setup for Cinnamon/Muffin. Reproduce the issue on Linux Mint with Cinnamon and verify that windowFrame: 'native' produces system decorations, including maximize, minimize, and close controls, without relying on Hyper's custom titlebar.