…using.

This commit introduces the necessary configuration and script to generate
Dart and Swift wrappers for Apple's EventKit framework.

Details:
- Updated pubspec.yaml with ffi, ffigen, objective_c, and swiftgen dependencies.
- Created tool/generate_code.dart to generate wrappers for EKEventStore, EKEvent, and EKCalendar.
- Configured the generator to target macOS to bypass iOS compilation limits on deprecated properties, and added a post-generation step to strip the iOS-unavailable 'birthdayPersonUniqueID' property from the generated Swift code.
- Added generated EventKit wrapper and binding files to .gitignore to keep the repository clean.

- Replaced the swiftgen generator script with a pure FfiGenerator approach directly on Objective-C headers. This eliminates the need for intermediate Swift/Objective-C wrapper classes (like EKEventStoreWrapper), significantly reducing complexity and avoiding Xcode linking crashes (FailedToLoadClassException).
- Updated generate_code.dart to specify exact entry points and headers for EventKit.framework, fetching native EKEventStore, EKEvent, EKCalendar, EKCalendarItem, and EKObject definitions directly.
- Refactored _retrieveEvents in lib/main.dart to use the type-safe, generated Dart APIs (eventsMatchingPredicate, objectAtIndex, etc.) instead of error-prone, manual objc.msgSend invocations and raw pointer casting.
- Fixed an issue where EKEvent.title (which returns an Objective-C NSString reference) incorrectly printed 'Instance of ObjCObject' by safely unwrapping it with package:objective_c's toDartString() method.

- Updated event fetching to parse startDate into a Dart DateTime.
- Refactored UI table to have distinct columns for Title, Date, and Time.
- Removed Sample Event boilerplate logic.

- Extracted CreateEventDialog into its own discrete file create_event_dialog.dart.
- Integrated CreateEventDialog into main.dart to open on the "Create Event" button press.
- Passed calendars explicitly to predicateForEventsWithStartDate to ensure fetching utilizes user's available calendars.
- Cleaned up leftover debugPrint statements and updated AppBar title.