Refactor event rendering with column-based event management

Improves event rendering by integrating event filtering directly into column data sources

Key changes:
- Moves event filtering responsibility to IColumnDataSource
- Simplifies event rendering pipeline by pre-filtering events per column
- Supports both date and resource-based calendar modes
- Enhances drag and drop event update mechanism

Optimizes calendar rendering performance and flexibility

src/types/ColumnDataSource.ts

@@ -1,13 +1,14 @@
 import { IResource } from './ResourceTypes';
-import { CalendarView } from './CalendarTypes';
+import { CalendarView, ICalendarEvent } from './CalendarTypes';
 
 /**
  * Column information container
  * Contains both identifier and actual data for a column
  */
 export interface IColumnInfo {
-  identifier: string;      // "2024-11-13" (date mode) or "person-1" (resource mode)
-  data: Date | IResource;  // Date for date-mode, IResource for resource-mode
+  identifier: string;           // "2024-11-13" (date mode) or "person-1" (resource mode)
+  data: Date | IResource;       // Date for date-mode, IResource for resource-mode
+  events: ICalendarEvent[];     // Events for this column (pre-filtered by datasource)
 }
 
 /**
@@ -28,6 +29,11 @@ export interface IColumnDataSource {
    */
   getType(): 'date' | 'resource';
 
+  /**
+   * Check if this datasource is in resource mode
+   */
+  isResource(): boolean;
+
   /**
    * Update the current date for column calculations
    * @param date - The new current date