Enhancement: Allow custom date format configuration

[ecorkran]

Feature Request

Allow users to configure their preferred date format instead of the hard-coded YYYY-MM-DD format.

Current Behavior

• Dates are always displayed and stored in YYYY-MM-DD format
• No way to customize this preference

Proposed Solution

Add a date format setting to user preferences/settings with common options:

• YYYY-MM-DD (ISO 8601, default)
• MM/DD/YYYY (US format)
• DD/MM/YYYY (European format)
• DD-MMM-YYYY (e.g., 21-Oct-2025)
• Maybe: Custom format string for power users

Implementation Notes

• Store preference in app settings/config
• Apply format consistently across:
  • Project date field display
  • Context output generation
  • Any date-related UI elements
• Keep internal storage as ISO format for consistency
• Only apply formatting for display

Rationale

• Different regions/users prefer different date formats
• Explicit setting is clearer than trying to detect from input
• Prevents ambiguity (is 01/02/2025 Jan 2 or Feb 1?)

Priority

Low - nice-to-have enhancement

Labels

enhancement