Question and permission panel becomes invisible after around 2s on some screens

[LikeSundayLikeRain]

Run into a really wired issue, the Ask user question/permission panel becomes invisible after around 2s on some screens. When moving mouse back to the panel area, it appears, but disappear when I move away.

It happens on my laptop screen, and the external display at home, but works fine on the external display at office, and reproduced on 2 different laptops(1 m1 pro, 1 m4 pro if that helps).

Screen.Recording.2026-08-05.at.11.00.49.PM.mov

[LikeSundayLikeRain]

seems related to #100

[LikeSundayLikeRain]

Tracked this down — opened #305 with a fix.

Root cause: the island is one big borderless, transparent NSPanel whose height is sized up-front from maxVisibleSessions (maxSessions * 90 + 60). With a large value (mine was 99) the window becomes ~8970pt tall — roughly an 18k-pixel-tall backing store on a Retina display, for a window that's ~95% transparent and only draws content in its top ~200pt. On macOS 26 the WindowServer drops compositing for a backing store that large once the surface goes idle, and nothing forces the settled card to repaint — so it renders blank until a mouse event forces a recomposition. That's the "invisible after ~2s, reappears on hover" behavior.

Why it was display-dependent: a 1× (non-HiDPI) external monitor's buffer is half the pixels and stays under the purge threshold — which is why the office external display worked while the built-in and the home external didn't.

Fix (#305): clamp the panel window height to the screen's visible height. The content is top-anchored and the session list already scrolls internally, so the window never needs to be taller than the screen.

Verified on macOS 26.6 with a release build using a real AskUserQuestion: instrumenting the live window showed it stayed isVisible=true / alpha=1.0 / occlusionState=.visible even while blank (so it wasn't a collapse, order-out, alpha, or occlusion-state issue) with an 8970pt frame; shrinking the window made the card stay visible with nothing else changed.