Function determineFallFromStance

Determines fall direction from current trigram stance

Some stances have inherent instability in certain directions. This function returns likely fall directions when balance is lost.

Korean stances and fall tendencies:

• 건 (Heaven): Forward bias - aggressive stance
• 태 (Lake): Backward bias - fluid retreating
• 리 (Fire): Forward bias - aggressive advance
• 진 (Thunder): Backward bias - explosive preparation
• 손 (Wind): Side bias - lateral movement
• 감 (Water): Backward bias - defensive flow
• 간 (Mountain): Backward bias - solid defense
• 곤 (Earth): Forward bias - grounding takedowns