Centralizes event position calculations into `PositionUtils` for consistency and reusability across managers and renderers.
Improves drag-and-drop functionality by emitting events for all-day event conversion and streamlining position calculations during drag operations.
Introduces `AllDayManager` and `AllDayEventRenderer` to manage and render all-day events in the calendar header. This allows dragging events to the header to convert them to all-day events.
Improves code organization and maintainability by separating concerns related to all-day event rendering, header management, and event resizing.
Moves all-day event rendering logic into a dedicated `AllDayEventRenderer` class, utilizing the factory pattern for event element creation.
Refactors `AllDayManager` to handle all-day row height animations, separated from `HeaderManager`.
Removes the `ResizeManager` and related functionality.
These changes aim to reduce code duplication, improve testability, and enhance the overall architecture of the calendar component.
