b3da46ac02
Add click handlers to the dialog component for all three targets that
close the dialog when clicking the backdrop area (outside the dialog box).
Uses event.target === event.currentTarget to distinguish backdrop clicks
from content clicks.
- :clj — inline onclick attribute
- :cljs — Replicant :on {:click handler}
- :squint — :on-click handler
- CSS: cursor: pointer on ::backdrop for affordance