Replace the fragmented drag implementations (preload.js, app/drag.js, cmd/panel.js custom handler) with a single robust system in preload.js. Key improvements: - Reduced hold delay from 300ms to 150ms for much snappier feel - Window position fetched eagerly on mousedown (overlaps with hold timer) so drag starts instantly when timer fires (no async wait after delay) - Window ID cached at init time (fetched once, never changes) - Added e.buttons === 0 safety check during mousemove - Event listeners use capture phase for reliable event interception - Removed -webkit-app-region CSS checks (only data-no-drag matters now) Removed duplicate implementations: - cmd/panel.js: removed custom drag handler (preload handles it) - cmd/panel.html: removed -webkit-app-region: no-drag CSS (not needed) - app/drag.js: replaced with no-op stub (settings.html import compat) Architecture: preload.js is the single source of truth. Windows opt out via data-no-drag on body (e.g., peek://page has its own canvas drag).