fix(vagrant): hip-anchors body-relative; leg-orientation procedural

User feedback: 'anchorpoints sind hüftgelenke und können sich nicht
frei drehen. hüfte bleibt zum körper statisch'.

Architecture:
- legs.parent = body (was lower_control). Hip position cascades from
  body.world.rot, so hips stay at body-frame left/right regardless of
  body rotation. lower_control virtual bone removed (no longer needed).
- Procedural 'leg_orientation' sets leg.local.rot = walk_dir - body.rot
  each frame, so leg.world.rot = walk_dir (independent of body cascade).
  Requires puppet v0.4.2 per-channel write_bone (walk_anim writes leg.scl
  while procedural writes leg.rot — disjoint channels).

Result: legs visually attach at body's anatomical left/right hips no
matter where body faces; stride oscillation aligns with WASD walk
direction. Hip position no longer drifts with walk direction.

init.lua

@@ -154,9 +154,17 @@ function M.init(ctx)
     puppet.play(state.player, "idle",       { loop = true })
     puppet.play(state.player, "idle_lower", { loop = true })
 
-    -- Procedural lower_control: applies the per-frame wedge rotation (set by update_lower_anim).
-    puppet.set_procedural(state.player, "lower_control", function(handle, dt)
-        puppet.write_bone(handle, "lower_control", { rot = state.lower_control_rot_deg })
+    -- Procedural leg-orientation: hips are body-relative (legs.parent=body, so
+    -- cascade-position follows body); the leg ROTATION is overridden each
+    -- frame to align with walk-direction (independent of body rotation).
+    -- leg.local.rot = walk_dir_world - body.world.rot → leg.world.rot = walk_dir.
+    -- write_bone allowed on leg.rot because walk_fwd_lower only writes leg.scl
+    -- (per-channel guard v0.4.2).
+    puppet.set_procedural(state.player, "leg_orientation", function(handle, dt)
+        local _, _, body_rot = puppet.bone_world_transform(handle, "body")
+        local leg_local_deg = state.lower_control_rot_deg - math.deg(body_rot)
+        puppet.write_bone(handle, "leg_l", { rot = leg_local_deg })
+        puppet.write_bone(handle, "leg_r", { rot = leg_local_deg })
     end)
 
     -- Furniture textures.