Extends event model to include optional description field
Enhances event rendering with:
- New description getter/setter in base event element
- Updated CSS grid layout for description display
- Dynamic description handling in event rendering
- Updated mock event data with descriptions
Improves visual information density and event context in calendar view
Converts CalendarConfig to a pure static configuration management class with improved initialization and dependency handling
Removes event bus dependencies and simplifies configuration loading
Adds static methods for config management and initialization
Improves flexibility and reduces class complexity
