Function addRecoveryPhase

addRecoveryPhase(
animation: SkeletalAnimation,
config?: RecoveryPhaseConfig,
): SkeletalAnimation
Add realistic recovery phase to technique animation

Korean: 기술 애니메이션에 복귀 단계 추가

Enhances technique animations with proper recovery phases following Korean martial arts principles of 복귀 (Bokgwi - recovery/return).

The recovery phase consists of two keyframes:
1. Intermediate recovery (60% of recovery duration):
  - Returns 80% toward neutral position
  - Reduces muscle tension to 40%
  - Uses ease-out for gradual deceleration
2. Final recovery (100% of recovery duration):
  - Fully returns to neutral stance
  - Relaxes muscle tension to 10%
  - Completes breath cycle
Parameters
- animation: SkeletalAnimation
  Base technique animation
- config: RecoveryPhaseConfig = {}
  Recovery phase configuration options
Returns SkeletalAnimation
Enhanced animation with recovery phase
Example
```
// Add default 220ms recovery to front kick
const kickWithRecovery = addRecoveryPhase(FRONT_KICK_ANIMATION);

// Add custom 180ms recovery with faster muscle release
const quickRecovery = addRecoveryPhase(JAB_ANIMATION, {
  duration: 0.18,
  intermediateMuscleTension: 0.3,
  finalMuscleTension: 0.05,
});
```
Korean
복귀단계추가
- Defined in systems/animation/core/RecoveryPhaseEnhancer.ts:122