fix(puppet): v0.4.1 — normalize target_local before clamp (south-flick fix)

When body's world.rot crosses ±π (e.g., body facing south), target_local
in the look-at-block could momentarily be ≈±2π. Without normalization,
the snap-branch wrote that raw value to state.angle, then rot_min/rot_max
clamp produced a discontinuous jump (head 'flicked sideways' when body
faced south, per manual interactive test).

Fix: normalize target_local to (-π, π] BEFORE the snap/slerp/rate-limit
branch and BEFORE clamp. Symmetric handling regardless of which smoothing
mode the bone uses.

init.lua

@@ -980,6 +980,12 @@ update_bone_recursive = function(p, b, dt)
         -- atan(dx, -dy): rot=0 when target is straight up, rot=pi/2 when target is to the right.
         local world_angle = math.atan(dx, -dy)
         local target_local = world_angle - pa
+        -- Normalize target_local to (-π, π] so snap/clamp don't see ±2π
+        -- discontinuities when parent.world.rot crosses ±π (e.g., body
+        -- facing south wraps parent.world.rot near ±π and target_local
+        -- can momentarily be ≈ ±2π without normalization → head flicks).
+        while target_local >  math.pi do target_local = target_local - 2 * math.pi end
+        while target_local < -math.pi do target_local = target_local + 2 * math.pi end
 
         -- Persistent state for slerp/rate-limit (carries angle across frames).
         local state = p.look_at_state[bid]