Two root-cause bugs fixed:
1. Port <button> elements inside ModuleBlock had pointer-events:auto (browser
default), so document.elementFromPoint() hit them instead of the RackSlot
behind them whenever the cursor was over an occupied slot. Fixed by toggling
body.rack-dragging during any drag, which applies a CSS rule that forces
pointer-events:none !important on .module-block and all descendants.
2. onDragMove pointer-position reconstruction (activatorEvent.clientX + delta.x)
was slightly off because delta is measured from the initial mousedown, not
the activation point. Replaced with a native window pointermove listener
(capture phase) that gives exact clientX/Y — no reconstruction needed.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
jason
55ee1dea93