Refactors event rendering to be event-driven

Moves event rendering logic into a dedicated EventRenderer class that uses a strategy pattern for different calendar types.

The rendering is now triggered by `GRID_RENDERED` and `CONTAINER_READY_FOR_EVENTS` events, emitted by the GridManager and NavigationManager respectively.

This change decouples the CalendarManager from direct event rendering and allows for more flexible and efficient event updates. The EventManager now has a method to fetch events for a given time period.

Removes direct calls to event rendering from CalendarManager. Improves animation transitions by using pre-rendered containers in the NavigationManager.

src/managers/EventManager.ts

@@ -119,6 +119,19 @@ export class EventManager {
         return this.events.find(event => event.id === id);
     }
 
+    /**
+     * Get events for a specific time period
+     */
+    public getEventsForPeriod(startDate: Date, endDate: Date): CalendarEvent[] {
+        return this.events.filter(event => {
+            const eventStart = new Date(event.start);
+            const eventEnd = new Date(event.end);
+            
+            // Event overlaps period if it starts before period ends AND ends after period starts
+            return eventStart <= endDate && eventEnd >= startDate;
+        });
+    }
+
     public addEvent(event: Omit<CalendarEvent, 'id'>): CalendarEvent {
         const newEvent: CalendarEvent = {
             ...event,