[macOS] Verify: reports carried over from window_manager

Start with a Flutter app using the Window API and reproduce the ten linked window_manager reports on macOS. Check the related nativeapi#59 issue for context, then verify each report and either fix it or record that it no longer occurs. Done means every checklist item has a verified result.

These were reported against window_manager 0.5.x, whose platform code is gone: window_manager 0.6.0 is rebuilt on nativeapi. None of them has been checked against nativeapi yet. Each needs a reproduction with nativeapi (a Flutter app on the Window API), then a fix or a note that it no longer happens. Tick them off here as they're checked.

Related: libnativeapi/nativeapi#59 (app-level hide on macOS).

• leanflutter/window_manager#565: buttons at the top of the window aren't clickable with a hidden title bar on macOS 26 Tahoe
• leanflutter/window_manager#171: a bar blocks the top of the content in native full screen
• leanflutter/window_manager#351: full screen together with always-on-top shows the menu bar and Dock
• leanflutter/window_manager#379: hide() while in full screen leaves a black screen
• leanflutter/window_manager#462: after setResizable(), the window can no longer be resized at all
• leanflutter/window_manager#501: on macOS 14+, the window can't be reopened after hiding it twice
• leanflutter/window_manager#543: crash when hiding the window from a global hotkey callback (with hotkey_manager)
• leanflutter/window_manager#541: setSize() hangs forever inside an integration test
• leanflutter/window_manager#481: background colour always black since Flutter 3.22.3 (reported on macOS)
• leanflutter/window_manager#360: app freezes after a hot restart when it starts in full screen (macOS, also reported on Windows 11)