Cannot close review window on Hyprland (wlroots)

[Youpen-y]

Issue: Cannot close review window on Hyprland (wlroots layer-shell has no title bar)

Problem

On wlroots-based Wayland compositors (tested on Hyprland), the /diff-review window cannot be closed by the user:

• No title-bar × button: the window has no decorations
• super+Q / Alt+F4 / Esc don't work: it isn't a regular toplevel, so
  compositor window actions (killactive, closewindow) don't apply
• The escape is killing the glimpse process (pkill -f glimpse), reload the extension or ending the pi session

Reproduce

1. Run pi on Hyprland (Wayland)
2. Execute /diff-review
3. Try to close the review window, there is no × button, and keyboard shortcuts (Esc, Alt+F4, super+Q) do nothing

Environment

• pi-review-loop: 0.3.0 (commit 3822e12)
• Compositor: Hyprland (Wayland)
• OS: Arch Linux
• glimpse backend: native (default; src/glimpse binary present)

Root cause

glimpse's native Linux backend renders the window as a layer-shell Overlay surface via gtk4-layer-shell, which by design carries no window decorations (no title bar, no × button) and is not managed as a regular toplevel by the compositor:

// glimpseui src/linux/src/main.rs:115-117
window.init_layer_shell();
window.set_layer(Layer::Overlay);
window.set_exclusive_zone(-1);

This is appropriate for glimpse's intended use (companion/overlay windows), but it leaves the review window with no affordance to close. glimpse does expose a close API (window.glimpse.close() → __glimpse_close → app.quit() at main.rs:218), but review-loop never calls it, there is no close button in the UI and no keyboard binding.

This only affects wlroots compositors. On macOS / Windows / X11 / GNOME-Wayland, gtk4-layer-shell falls back to a normal decorated toplevel (those compositors don't implement wlr-layer-shell), so the system × button is present.

Expected behavior

The review window should be closable on all platforms. On wlroots (where there is no system title bar), review-loop should provide its own in-page close button, since the window lacks native window decorations.

Note

I have a fix ready: detect Hyprland in the bridge via process.env.HYPRLAND_INSTANCE_SIGNATURE, inject a flag into the page HTML, and reveal an in-page × button wired to glimpse's existing window.glimpse.close() API. If this approach sounds reasonable, hope the PR can be given some consideration.