Refactors event handling and grid rendering

Improves calendar performance and data flow by streamlining event emissions and grid rendering logic.

- Replaces generic CONFIG_UPDATE events with REFRESH_REQUESTED
  for more specific refresh triggers.
- Removes redundant grid re-renders on DATE_CHANGED and
  WEEK_CHANGED events, delegating navigation to NavigationManager.
- Introduces VIEW_CHANGED and DATE_CHANGED events for calendar
  mode and date selection, respectively.
- NavigationManager now handles date validation.
- Moves rendering logic from NavigationManager to NavigationRenderer.
- Syncs scroll position based on PERIOD_CHANGED instead of
  NAVIGATION_ANIMATION_COMPLETE.

This change optimizes the calendar's responsiveness and reduces
unnecessary re-renders, leading to a smoother user experience.

src/renderers/ColumnRenderer.ts

@@ -24,7 +24,7 @@ export interface ColumnRenderContext {
  * Date-based column renderer (original functionality)
  */
 export class DateColumnRenderer implements ColumnRenderer {
-  private dateCalculator: DateCalculator;
+  private dateCalculator!: DateCalculator;
 
   render(columnContainer: HTMLElement, context: ColumnRenderContext): void {
     const { currentWeek, config } = context;