Refines the event grid layout algorithm to more accurately
identify conflicting events for stacking within the grid.
Now uses an expanding search to find chains of conflicting events,
ensuring that all events that should be grouped together are
correctly identified.
Introduces a coordinator to manage event layout calculations,
separating this logic from rendering.
It calculates stack levels and allocates event columns for
improved visual organization of calendar events.
Moves complex layout determination logic (grid grouping, stack levels, positioning) from `EventRenderer` to a new `EventLayoutCoordinator` class.
Delegates layout responsibilities to the coordinator, significantly simplifying the `EventRenderer`'s `renderColumnEvents` method. Refines `EventStackManager` by removing deprecated layout methods, consolidating its role to event grouping and core stack level management.
Improves modularity and separation of concerns within the rendering pipeline.
