Narrow the pose-capture discrepancy to the harness and lock bone posing

src/test/capture_npc_pose.gd

@@ -261,8 +261,6 @@ func _shoot() -> void:
 	while FileAccess.file_exists(path):
 		path = dir.path_join("%s-v%d.png" % [base, index])
 		index += 1
-	var hip_bone: int = int(_avatar._bone_indices.get("HipL", -1))
-	var knee_bone: int = int(_avatar._bone_indices.get("KneeL", -1))
 	var img: Image = root.get_texture().get_image()
 	var err := img.save_png(path)
 	print("%s -> err=%d" % [base, err])

src/test/tests/test_npc_character.gd

@@ -147,6 +147,38 @@ func test_skinned_model_loads_and_keeps_the_head_contract() -> bool:
 	avatar.free()
 	return a and b and c
 
+## The pose harness captures frames, but a regression here is cheap to catch:
+## the pose logic must reach the skeleton bones, not only the proxy pivots.
+func test_pose_reaches_the_skeleton_bones() -> bool:
+	var avatar := _avatar(Rules.NpcType.TOURIST, 55)
+	var sk := avatar._skeleton
+	var hip: int = int(avatar._bone_indices["HipL"])
+	var knee: int = int(avatar._bone_indices["KneeL"])
+	var rest_hip := sk.get_bone_rest(hip).basis.get_rotation_quaternion()
+	var rest_knee := sk.get_bone_rest(knee).basis.get_rotation_quaternion()
+	avatar.arrived = true
+	avatar.npc.intent = "sit"
+	for _i in 45:
+		avatar._animate(1.0 / 60.0)
+	var sit_hip := sk.get_bone_pose_rotation(hip)
+	var sit_knee := sk.get_bone_pose_rotation(knee)
+	var a := TestUtils.check(not sit_hip.is_equal_approx(rest_hip),
+		"seated pose rotates the HipL bone away from rest")
+	var b := TestUtils.check(not sit_knee.is_equal_approx(rest_knee),
+		"seated pose rotates the KneeL bone away from rest")
+	var c := TestUtils.check(avatar._rig.position.y < -0.25,
+		"seated pose lowers the rig (%.3f)" % avatar._rig.position.y)
+	# Returning to idle must restore the rest orientation, not leave the sit pose.
+	avatar.arrived = false
+	avatar.npc.intent = "roam"
+	avatar.velocity = Vector3.ZERO
+	for _i in 120:
+		avatar._animate(1.0 / 60.0)
+	var d := TestUtils.check(sk.get_bone_pose_rotation(hip).is_equal_approx(rest_hip),
+		"idle restores the HipL rest orientation")
+	avatar.free()
+	return a and b and c and d
+
 func test_character_selection_is_deterministic_and_complete() -> bool:
 	var expected := {
 		Rules.NpcType.TOURIST: "npc_casual",