add Jalali (Persian) calendar support

[Ayyoubzadeh]

• Resolves: #
• Target version: main

Summary

This PR adds comprehensive Jalali calendar (Persian/Shamsi calendar) support to the Deck application, enabling Persian-speaking users to work with their native calendar system while maintaining full backward compatibility.

Key Features:

• Automatic Locale Detection: Seamlessly switches between Gregorian and Jalali calendars based on user locale
• Persian Calendar Integration: Full support for Jalali date conversion, formatting, and display
• Enhanced Components: New due date selector and badge components with calendar-aware functionality
• Localized Experience: Persian day names, month names, and relative time expressions
• Backward Compatibility: Existing functionality remains unchanged for non-Persian locales

Technical Implementation:

• Added moment-jalaali dependency for Jalali calendar calculations
• Created jalaliCalendar.js helper with comprehensive date conversion functions
• Implemented enhancedReadableDate mixin for calendar-aware date formatting
• Enhanced existing components (EnhancedDueDateSelector, EnhancedDueDate) with Jalali support
• Added automatic initialization system that detects locale changes
• Comprehensive test coverage for all calendar functions
• Full documentation in docs/JALALI_CALENDAR.md

User Experience:

• Persian users automatically see Jalali calendar dates throughout the application
• Due dates, timestamps, and relative times are displayed in Persian format
• Week starts on Saturday (as per Persian calendar tradition)
• All date pickers and displays respect the user's calendar preference

TODO

• Update Persian localization files with new calendar-related strings
• Add visual calendar grid picker for Jalali dates (future enhancement)
• Consider adding Persian holiday support
• Performance testing with large date ranges
• User acceptance testing with Persian-speaking users

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Documentation (manuals or wiki) has been updated or is not required
• Backward compatibility maintained
• Locale detection properly implemented
• Date conversion functions tested
• Component integration verified
• Error handling implemented
• Performance considerations addressed

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