Feature: Task Start Date

We've added a new start date feature to tasks, giving you better control over when tasks become active:

• Tasks with future start dates won't appear in focus mode until their start date arrives
• Auto-scheduling now respects start dates and won't schedule tasks before they're ready to start
• Added visual indicators for upcoming tasks in task list view
• New filter option to hide upcoming tasks
• Ability to sort and filter by start date

Calendar Improvements

• Added week start day setting in Calendar Settings UI to choose between Monday and Sunday as first day of week
• Expanded timezone options in user settings to include a more comprehensive global list

Important Bug Fixes

• Fixed all-day events appearing on the wrong day for Google Calendar events due to timezone handling
• Fixed Outlook all-day event creation and display issues:
  • Events now use correct UTC midnight times required by Outlook
  • Single-day events properly extend to meet Outlook's 24-hour duration requirement
  • Fixed display issues where events were showing on incorrect dates