Quick-access AirDrop from the notch panel. Tap the card body, pick
files via NSOpenPanel, hand off to NSSharingService(.sendViaAirDrop).
No private APIs, no entitlements, no network — just a thin wrapper
around the same AirDrop API Finder uses.
Design constraint: drag-and-drop is intentionally not implemented.
MioIsland's notch panel auto-collapses on click-outside, which
breaks the Cmd-Tab-to-Finder / grab / drag-back workflow before
the drop target reaches. Tap-to-choose is rock solid by comparison.
Requires MioIsland host v2.2.0+ (panel size clamp floor was
lowered to 120pt in that release).
