Enhances event layout engine with advanced rendering logic

Introduces sophisticated event layout algorithm for handling complex scheduling scenarios

Adds support for:
- Grid and stacked event rendering
- Automatic column allocation
- Nested event stacking
- Threshold-based event grouping

Improves visual representation of overlapping and concurrent events

src/v2/features/headerdrawer/HeaderDrawerRenderer.ts

@@ -77,7 +77,7 @@ export class HeaderDrawerRenderer {
 
     // Create header item
     const item = document.createElement('swp-header-item');
-    item.dataset.id = payload.eventId;
+    item.dataset.eventId = payload.eventId;
     item.dataset.itemType = payload.itemType;
     item.dataset.date = payload.sourceDate;
     item.dataset.duration = String(payload.duration);