Enables event resizing via drag handles

Adds a resize handle manager to handle mouse hover
effects on calendar events and display a resize indicator.

This allows users to visually identify and initiate
event resizing by hovering near the bottom edge of an event.

src/factories/ManagerFactory.ts

@@ -8,6 +8,7 @@ import { ViewManager } from '../managers/ViewManager';
 import { CalendarManager } from '../managers/CalendarManager';
 import { DragDropManager } from '../managers/DragDropManager';
 import { AllDayManager } from '../managers/AllDayManager';
+import { ResizeHandleManager } from '../managers/ResizeHandleManager';
 import { CalendarManagers } from '../types/ManagerTypes';
 
 /**
@@ -39,6 +40,7 @@ export class ManagerFactory {
     const viewManager = new ViewManager(eventBus);
     const dragDropManager = new DragDropManager(eventBus);
     const allDayManager = new AllDayManager(eventManager);
+    const resizeHandleManager = new ResizeHandleManager();
     
     // CalendarManager depends on all other managers
     const calendarManager = new CalendarManager(
@@ -49,7 +51,7 @@ export class ManagerFactory {
       scrollManager
     );
 
-    
+
     return {
       eventManager,
       eventRenderer,
@@ -59,7 +61,8 @@ export class ManagerFactory {
       viewManager,
       calendarManager,
       dragDropManager,
-      allDayManager
+      allDayManager,
+      resizeHandleManager
     };
   }
 
@@ -67,9 +70,10 @@ export class ManagerFactory {
    * Initialize all managers in the correct order
    */
   public async initializeManagers(managers: CalendarManagers): Promise<void> {
-    
+
     try {
       await managers.calendarManager.initialize?.();
+      managers.resizeHandleManager.initialize();
     } catch (error) {
       throw error;
     }

src/managers/ResizeHandleManager.ts

@@ -0,0 +1,89 @@
+export class ResizeHandleManager {
+  private resizeZoneHeight =15; // Must match CSS ::after height
+  private lastHoveredEvent: HTMLElement | null = null;
+
+  public initialize(): void {
+    this.setupEventListeners();
+  }
+
+  private setupEventListeners(): void {
+
+    // Listen to global mouseover from document
+    document.addEventListener('mouseover', (e: MouseEvent) => {
+      this.handleGlobalMouseOver(e);
+    });
+
+    document.addEventListener('mousemove', (e: MouseEvent) => {
+      this.handleGlobalMouseMove(e);
+    });
+
+    document.addEventListener('mouseout', (e: MouseEvent) => {
+      this.handleGlobalMouseOut(e);
+    });
+  }
+
+  private handleGlobalMouseOver(e: MouseEvent): void {
+    const target = e.target as HTMLElement;
+    const eventElement = target.closest<HTMLElement>('swp-day-columns swp-event');
+
+    if (eventElement) {
+      this.lastHoveredEvent = eventElement;
+    }
+  }
+
+  private handleGlobalMouseMove(e: MouseEvent): void {
+    // Check all events to see if mouse is in their resize zone
+    const events = document.querySelectorAll<HTMLElement>('swp-day-columns swp-event');
+
+    events.forEach(eventElement => {
+      const rect = eventElement.getBoundingClientRect();
+      const mouseY = e.clientY;
+      const mouseX = e.clientX;
+
+      // Check if mouse is within element bounds horizontally
+      const isInHorizontalBounds = mouseX >= rect.left && mouseX <= rect.right;
+
+      // Check if mouse is in bottom 25px of the element
+      const distanceFromBottom = rect.bottom - mouseY;
+      const isInResizeZone = distanceFromBottom >= 0 && distanceFromBottom <= this.resizeZoneHeight;
+
+      if (isInHorizontalBounds && isInResizeZone) {
+        this.showResizeIndicator(eventElement);
+        console.log('✅ In resize zone - bottom 25px');
+      } else {
+        this.hideResizeIndicator(eventElement);
+      }
+    });
+  }
+
+  private showResizeIndicator(eventElement: HTMLElement): void {
+    // Check if indicator already exists
+    let indicator = eventElement.querySelector<HTMLElement>('swp-resize-indicator');
+
+    if (!indicator) {
+      indicator = document.createElement('swp-resize-indicator');
+      eventElement.appendChild(indicator);
+    }
+
+    eventElement.setAttribute('data-resize-hover', 'true');
+  }
+
+  private hideResizeIndicator(eventElement: HTMLElement): void {
+    const indicator = eventElement.querySelector<HTMLElement>('swp-resize-indicator');
+    if (indicator) {
+      indicator.remove();
+    }
+    eventElement.removeAttribute('data-resize-hover');
+  }
+
+  private handleGlobalMouseOut(e: MouseEvent): void {
+    const target = e.target as HTMLElement;
+    const eventElement = target.closest<HTMLElement>('swp-day-columns swp-event');
+
+    if (eventElement) {
+      // Don't remove immediately - let mousemove handle it
+    }
+  }
+
+  
+}

src/types/ManagerTypes.ts

@@ -13,6 +13,7 @@ export interface CalendarManagers {
   calendarManager: CalendarManager;
   dragDropManager: unknown; // Avoid interface conflicts
   allDayManager: unknown; // Avoid interface conflicts
+  resizeHandleManager: ResizeHandleManager;
 }
 
 /**
@@ -70,6 +71,10 @@ export interface AllDayManager extends IManager {
   [key: string]: unknown; // Allow any properties from actual implementation
 }
 
+export interface ResizeHandleManager extends IManager {
+  // ResizeHandleManager handles hover effects for resize handles
+}
+
 export interface ResourceData {
   resources: Resource[];
   assignments?: ResourceAssignment[];