Function isPlayerIncapacitatedByBodyDamage

Check if player is incapacitated by body part damage.

Korean: 신체부위 무력화 확인

Determines if the player can continue fighting based on body part health. Player is incapacitated if:

• Head is at 0 HP (unconscious)
• Both legs are at 0 HP (cannot stand)
• Aggregate health is below 10%