Sets up calendar package with core infrastructure

Adds core calendar package components including:
- Base services for events, resources, and settings
- Calendar app and orchestrator
- Build and bundling configuration
- IndexedDB storage setup

Prepares foundational architecture for calendar functionality

packages/calendar/src/core/ScrollManager.ts

@@ -0,0 +1,42 @@
+export class ScrollManager {
+  private scrollableContent!: HTMLElement;
+  private timeAxisContent!: HTMLElement;
+  private calendarHeader!: HTMLElement;
+  private headerDrawer!: HTMLElement;
+  private headerViewport!: HTMLElement;
+  private headerSpacer!: HTMLElement;
+  private resizeObserver!: ResizeObserver;
+
+  init(container: HTMLElement): void {
+    this.scrollableContent = container.querySelector('swp-scrollable-content')!;
+    this.timeAxisContent = container.querySelector('swp-time-axis-content')!;
+    this.calendarHeader = container.querySelector('swp-calendar-header')!;
+    this.headerDrawer = container.querySelector('swp-header-drawer')!;
+    this.headerViewport = container.querySelector('swp-header-viewport')!;
+    this.headerSpacer = container.querySelector('swp-header-spacer')!;
+
+    this.scrollableContent.addEventListener('scroll', () => this.onScroll());
+
+    // Synkroniser header-spacer højde med header-viewport
+    this.resizeObserver = new ResizeObserver(() => this.syncHeaderSpacerHeight());
+    this.resizeObserver.observe(this.headerViewport);
+    this.syncHeaderSpacerHeight();
+  }
+
+  private syncHeaderSpacerHeight(): void {
+    // Kopier den faktiske computed height direkte fra header-viewport
+    const computedHeight = getComputedStyle(this.headerViewport).height;
+    this.headerSpacer.style.height = computedHeight;
+  }
+
+  private onScroll(): void {
+    const { scrollTop, scrollLeft } = this.scrollableContent;
+
+    // Synkroniser time-axis vertikalt
+    this.timeAxisContent.style.transform = `translateY(-${scrollTop}px)`;
+
+    // Synkroniser header og drawer horisontalt
+    this.calendarHeader.style.transform = `translateX(-${scrollLeft}px)`;
+    this.headerDrawer.style.transform = `translateX(-${scrollLeft}px)`;
+  }
+}