Wire up SortableJS in app.js to enable dragging task cards between
Kanban columns. On drop, fires htmx PUT requests to the appropriate
Board handler (Start/Pause/Resume/Complete) based on the column
transition. Invalid transitions are reverted. Sortable instances are
destroyed and recreated after htmx swaps to prevent memory leaks.
Also centralizes detail panel open/close/edit helpers and Escape key
handling.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
