Summary

Fix the calendar view time formatting in boardBody.js to use standard AM/PM notation
instead of confusing single-letter abbreviations (like "a"/"p" or locale-specific symbols
such as 上/下/中 in CJK locales).

Changes

1. Fix hour notation

• Updated the FullCalendar time format configuration in boardBody.js to use
  non-localized h:mma format (e.g., "2:30PM" instead of "2:30p")
• This prevents confusing time labels for users in non-Latin locales

2. Add complete time format coverage

• Added explicit format overrides for all FullCalendar time display contexts:
  • extraSmallTimeFormat: h(:mm)a
  • smallTimeFormat: h(:mm)a
  • mediumTimeFormat: h:mma
  • hourFormat: ha
  • noMeridiemTimeFormat: h:mm
• Ensures consistent AM/PM display across all calendar views
  (day, week, agenda, etc.)

Testing

• Verified calendar renders times with full "am"/"pm" labels
• Tested across day, week, and agenda views
• Confirmed no regression in calendar event display

Related issues
closes #6054