Adds event resizing functionality to calendar

Introduces ResizeManager to handle dynamic event duration updates

Implements smooth height animation and grid-based snapping
Adds resize event tracking and timestamp display during resizing
Integrates resize handle creation and pointer event management

src/v2/managers/DragDropManager.ts

@@ -75,6 +75,10 @@ export class DragDropManager {
 
   private handlePointerDown = (e: PointerEvent): void => {
     const target = e.target as HTMLElement;
+
+    // Ignore if clicking on resize handle
+    if (target.closest('swp-resize-handle')) return;
+
     const eventElement = target.closest('swp-event') as HTMLElement;
 
     if (!eventElement) return;