feat: Port Calendar Drag & Drop to pointerdrag library - #76

Review

Thanks for the pointerdrag port and the resize timezone fix. Direction is right, and the day/week move/resize path (live client* + getBoundingClientRect() + scrollTop, mode bag on kronDrag/state) is a solid replacement for the old Object.extend(drag, …) pattern. The naive yyyy-MM-dd HH:mm:ss resize payload is a real bugfix.

Depends on horde/Core#211 (pointerdrag.js); that one is approved — merge core first (or in lockstep). Pierre’s confirmation on #74 covers month + day/week for the reported scroll case.

Request changes: all-day week/workweek moves

allday-move uses:

new HordeDraggable(event.value.nodeId, { threshold: 5 });

with no ghosting: true.

Head events are position: relative. Without a ghost, the source stays under the cursor and keeps hit-testing. elementFromPoint → closest('.horde-drop-target') resolves to the original day cell → onDrop hits if (drop == el.up()) return and never moves the event to another day.

Old dragdrop2 always built a ghost and hid the source when not in caption/ghosting mode, so cross-day all-day drops used to work.

Suggested fix: enable ghosting: true for all-day (and/or set pointer-events: none on the source while active).

Also, onDragStart / onDrag for allday-move measure against .kronolithViewBody, while minTop / maxTop / clamps come from the view head. Wrong frame for the rubber-band UI (the drop hit-testing issue is the functional break).

Other notes (non-blocking)

• Day/week timed move still will not track a pure wheel scroll until the next pointermove (core does not replay on external scroll). Month is fine (fixed ghost). Optional: scroll listener in core or here if #74 must hold for timed moves without mouse movement.
• PR title is branch-like (feat/pointerdrag port); commit messages are fine.
• No composer pin that core includes pointerdrag.js — document merge order or bump the core requirement once released.

Test matrix

• Month: drag + wheel mid-drag → ghost follows; drop on correct day
• Day/week timed move/resize
• Week all-day → other day (currently expected broken)
• Drag then release without crossing threshold → opens event (no stale dialog)
• Resize handle vs move (innermost wins)

Request changes for the all-day drop regression before merge.