ZoneRental

Internal refactoring: Migrated the three largest command classes from Java to Kotlin.

Kotlin Conversions

• DurationCommand.kt - Migrated from Java (439 → 329 lines, 25% reduction)

  • Leverages existing DurationAction/DurationResult sealed classes
  • When expressions for action handling
  • TimeUtils integration for duration parsing

• GroupCommand.kt - Migrated from Java (777 → 599 lines, 23% reduction)

  • Data classes for PendingGroupAction and ParseResult
  • Collection functions for region parsing
  • Simplified tab completion with caching

• TpCommand.kt - Migrated from Java (463 → 310 lines, 33% reduction)

  • Smart casts for block data types
  • Companion object with material sets for block checks
  • Streamlined 3D safe location algorithm

Technical Notes

• No user-facing changes - all commands work identically
• Total line reduction: ~26% across migrated commands
• Improved type safety and null handling