Adds header drawer event rendering support

Extends calendar rendering to support all-day events in header drawer

Implements rendering logic for all-day events in header drawer:
- Fetches events for visible date range
- Filters and creates header items for all-day events
- Dynamically positions events with color classes
- Expands header drawer when events are present

Enhances event persistence with header drop detection

src/v2/core/CalendarOrchestrator.ts

@@ -2,13 +2,15 @@ import { IRenderer, IRenderContext } from './IGroupingRenderer';
 import { buildPipeline } from './RenderBuilder';
 import { EventRenderer } from '../features/event/EventRenderer';
 import { ScheduleRenderer } from '../features/schedule/ScheduleRenderer';
+import { HeaderDrawerRenderer } from '../features/headerdrawer/HeaderDrawerRenderer';
 import { ViewConfig } from './ViewConfig';
 
 export class CalendarOrchestrator {
   constructor(
     private allRenderers: IRenderer[],
     private eventRenderer: EventRenderer,
-    private scheduleRenderer: ScheduleRenderer
+    private scheduleRenderer: ScheduleRenderer,
+    private headerDrawerRenderer: HeaderDrawerRenderer
   ) {}
 
   async render(viewConfig: ViewConfig, container: HTMLElement): Promise<void> {
@@ -48,8 +50,11 @@ export class CalendarOrchestrator {
     // Render schedule unavailable zones (før events)
     await this.scheduleRenderer.render(container, filter);
 
-    // Render events med hele filter (date + resource)
+    // Render timed events in grid
     await this.eventRenderer.render(container, filter);
+
+    // Render allDay events in header drawer
+    await this.headerDrawerRenderer.render(container, filter);
   }
 
   private selectRenderers(viewConfig: ViewConfig): IRenderer[] {