feat: ApiTests IK tests

ApiTests/ApiTests.zip

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:d62187919d5ed82d566f1addadf19a2752bedc077d130736c8ca6da756570855
-size 55899477
+oid sha256:848713b91a4f00f3c760cfd33daf21caed6fd7f4d6a48e736d4b4800bf2af8c4
+size 58617726

ApiTests/metadata.yaml

@@ -1,6 +1,6 @@
 Name: "API Tests"
 Type: Project
-Version: "1.2"
+Version: "1.4"
 EngineVersion:
   Min: "2026.2"
   Behaviour: Hide
@@ -11,7 +11,11 @@ Description: >
   over the gated Step() loop and checks bit-exact repeatability: the Panda and Piper arms; the
   Unitree Go2 (in-engine and external locomotion) with LiDAR-scan, RGBD-camera and reset_scene
   checks; and the Unitree G1 three- and five-finger humanoids in base, engine, external,
-  IK-engine and IK-external variants. run_all_tests.py sweeps every scene and reports pass/fail.
+  IK-engine and IK-external variants. The four arm-IK scenes additionally assert that the arm
+  actually tracks its commanded target, not just that the run replays identically. A
+  pick-and-place scene shows engine-side C# driving a G1 through a waypoint sequence with
+  draggable target empties and debug gizmos. run_all_tests.py sweeps every scene and reports
+  pass/fail, installing requirements.txt into its test interpreter first.
 Tags:
   - tests
   - determinism