Enhances header drawer rendering to handle multi-day events
- Calculates column span for events across multiple days
- Adds support for events spanning beyond visible date range
- Updates event data attributes to include start and end dates
Extends calendar rendering to support all-day events in header drawer
Implements rendering logic for all-day events in header drawer:
- Fetches events for visible date range
- Filters and creates header items for all-day events
- Dynamically positions events with color classes
- Expands header drawer when events are present
Enhances event persistence with header drop detection
Adds expanded state tracking for header drawer during drag
Ensures drawer remains in the correct expanded/collapsed state based on initial condition
Improves user experience by maintaining consistent drawer state
Introduces HeaderDrawerRenderer and HeaderDrawerLayoutEngine to support dragging events into an all-day header drawer
Enables dynamic event placement and conversion between timed and all-day events through new drag interactions
Implements flexible layout calculation for header items with column and row management
Extends DragDropManager to handle header zone interactions
Adds new event types for header drag events
