Optimizes header event handling and all-day display

Improves performance by early-exiting header event processing when no drag operation is active.
Ensures the all-day container height is re-evaluated after the mouse leaves the header area, maintaining correct layout.

src/managers/AllDayManager.ts

@@ -51,6 +51,12 @@ export class AllDayManager {
       console.log('🏗️ AllDayManager: Received request to ensure all-day container exists');
       this.ensureAllDayContainer();
     });
+
+    // Listen for header mouseleave to recalculate all-day container height
+    eventBus.on('header:mouseleave', () => {
+      console.log('🔄 AllDayManager: Received header:mouseleave, recalculating height');
+      this.checkAndAnimateAllDayHeight();
+    });
   }
 
   /**

src/managers/HeaderManager.ts

@@ -55,6 +55,14 @@ export class HeaderManager {
 
     // Use mouseenter instead of mouseover to avoid continuous firing
     this.headerEventListener = (event: Event) => {
+      // OPTIMIZED: Check for active drag operation FIRST before doing any other work
+      const isDragActive = document.querySelector('.dragging') !== null;
+      
+      if (!isDragActive) {
+        // Ingen drag operation, spring resten af funktionen over
+        return;
+      }
+      
       const target = event.target as HTMLElement;
       
       console.log('🖱️ HeaderManager: mouseenter detected on:', target.tagName, target.className);
@@ -74,14 +82,6 @@ export class HeaderManager {
       }
       
       if (allDayContainer) {
-        // SMART CHECK: Only calculate target date if there's an active drag operation
-        const isDragActive = document.querySelector('.dragging') !== null;
-        
-        if (!isDragActive) {
-          console.log('⏭️ HeaderManager: No active drag operation, skipping target date calculation');
-          return;
-        }
-        
         console.log('📍 HeaderManager: Active drag detected, calculating target date...');
         
         // Calculate target date from mouse X coordinate