- Move trash button drop listener out of setupDrag() to an IIFE so it
only registers once (was accumulating listeners on every render() call,
causing multiple toast messages on single drop).
- Fix rectangle selection mousedown handler: use optional chaining on
closest() for safety with text nodes; avoid calling render() inside
mousedown (which would detach the event target's children mid-handler)
and instead just remove .selected class directly from the DOM.
Zaki
a97d05412e