Fix alt+1-9 quick menu on MacOS

Small bug fixes with Quick Alt Menu:
Close alt menu on Window change, fix alt menu focusing issues.

v1.0 → v3.0 — What Changed

v1.x — Modal navigator. Enter a mode with Ctrl+Alt+N, use h/j/k/l to cone-search for the nearest element directionally. Hint labels for quick-jump. Three explicit modes (Normal, Navigation, Editing).

v2.0 — Complete architectural rewrite. Removed all modal switching. Replaced with a modeless Alt-layer — hold Alt and everything is one keystroke away. Added element picker (Alt+F), text search (Alt+/), caret mode (Alt+V), tab picker, marks, quick actions palette, physics-based scrolling, clipboard ops, section navigation, and focus history.

v2.1–v2.7 — Zone-based picker with spotlight dimming, progressive visual hierarchy, keyboard layout awareness, shadow DOM traversal, prefers-reduced-motion support, leader lines, priority-based quick-pick scoring, trusted .click() for web apps.

v3.0 — Stability and polish release. Spotlight uses SVG mask with soft edges, single clip-path (no overlap artifacts), fresh element scan on every picker open, search restricted to visible text only, caret fully disappears on exit. Scoring extracted and standardized. Crash fixes.

Improvements:
- Navigator now remembers the last focused element; and focuses on that when resuming navigation mode.
- Hidden buttons will show when focused by Navigator

Some stability fixes