Feature: `/repair` command

## Feature: `/repair` command

### Description
Allows players to fully repair the item they are currently holding in hand.

### Use case
Let players spend resources to repair tools and armor.

### Suggestion
- Command: `/repair`
- Unlock with 4 Netherite Ingot via `/boutique`
- Permission: `frenchdiscord.repair`
- Can only repair one item at a time (no inventory repair)

### Status
🔴 Not started