Description

Add the ability to create calendar events directly from the timeline by double-clicking on free space in the left half. Features a Spotlight-like autocomplete popover with recent event suggestions, calendar name matching, live duration lookup from EventKit, and full undo/redo support.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Build/CI change

Related Issues

N/A

Changes Made

• EventCreationPopover — new inline popover with calendar picker (CalendarPickerCompact), name field with Spotlight-like autocomplete (prefix > substring > fuzzy matching), duration quick-chips (30/45/60/90) + NumericInputField, and keyboard-driven flow (Cmd+Up/Down cycles calendars, arrow keys for suggestions, Tab/Enter to apply)
• RecentEventsStore — new service that persists up to 20 recently created event templates in UserDefaults, with search (prefix/substring/fuzzy) and live duration resolution from EventKit via stored eventId
• TimelineView — double-click on free space (left half) opens creation popover as a floating overlay (outside ScrollView to avoid clipping), with full undo/redo for created events (Cmd+Z deletes, Cmd+Shift+Z restores)
• EventUndoManager — added .create case to UndoableChange enum with recordCreate(), pushRedoForUndoneCreate(), and updateTopUndoCreateId() for round-trip undo/redo with event ID tracking
• CalendarService — added eventDurationMinutes(identifier:) for live duration lookup from EventKit
• SessionFlowApp — registered RecentEventsStore as @EnvironmentObject
• Last selected calendar persisted via @AppStorage across sessions
• Unified Suggestion enum mixes recent events and calendar matches in one dropdown, with calendar icon to distinguish types

Screenshots/Videos

N/A

Testing Checklist

• App builds without errors or warnings
• All existing features still work
• New feature works as expected
• Tested with empty calendar
• Tested with calendar containing events
• Tested edge cases (if applicable)
• UI looks correct in different window sizes (if UI changes)
• Calendar permissions work correctly (if calendar changes)
• No crashes or memory leaks

Documentation

• Updated CHANGELOG.md under [Unreleased]
• Updated README.md (if needed)
• Added code comments for complex logic

Additional Notes

• The popover is anchored near the top of the view (22% offset) so suggestion list grows downward only
• Calendar list sorts non-session calendars first (alphabetically), then work/side/deep calendars
• Esc dismisses the popover; clicking the dimmed background also dismisses

Checklist

• My code follows the project's coding standards
• I have tested my changes thoroughly
• My changes generate no new warnings
• If adding new files, I have updated project.pbxproj