Add custom ESLint rule that warns when class properties or constructor
parameters use primitive types (number, string, boolean) where a value
object exists in src/value-objects/.
The rule auto-discovers value objects from the directory and maps
property names (e.g. 'health' → 'Health') to suggest the correct type.
Found 4 warnings on the codebase:
- MagicalObject.ts: #health: number property
- MagicalObject.ts: health: number constructor param
- MagicalWeapon.ts: health: number constructor param
- HealingObject.ts: health: number constructor param
