Function mirrorGuardPose

mirrorGuardPose(pose: StanceGuardPose): StanceGuardPose
Mirror a guard pose for left/right stance laterality.

Korean: 자세 좌우 대칭

Creates a mirror-image guard pose by swapping left and right limb positions and negating lateral (Y-axis and Z-axis) rotations. This enables authentic left/right stance differentiation in Korean martial arts.

Key transformations:
- Swap leftArm ↔ rightArm bone rotations
- Negate Y rotation (lateral twist)
- Negate Z rotation (roll)
- Preserve X rotation (forward/back bend)
- Keep weight distribution and breathing range unchanged
Parameters
- pose: StanceGuardPose
  Original guard pose to mirror
Returns StanceGuardPose
Mirrored guard pose with swapped and negated rotations
Example
```
// Create right-handed version of a left-handed guard
const leftGeonGuard = GEON_HIGH_GUARD_POSE;
const rightGeonGuard = mirrorGuardPose(leftGeonGuard);

// leftGeonGuard has left hand forward
// rightGeonGuard has right hand forward (mirrored)
```
Korean
방어포즈대칭
- Defined in types/skeletal.ts:719