Auto-select gripper state from z coordinate in pose mode

- Add resolve_gripper_from_z(): z>=55 → down (open), z<55 → up (closed),
  overlap range prefers down
- Remove --up flag from pose subparser (fully auto-detected from --z)
- joints mode retains manual --up flag
- Update cached state to match latest run

tools/.udp_control_state.json

@@ -1,8 +1,8 @@
 {
-  "height": -290,
-  "j2": -66,
-  "j3": 145,
-  "j4": -44,
-  "j5": -100,
+  "height": 0,
+  "j2": -90,
+  "j3": 140,
+  "j4": 25,
+  "j5": 81,
   "j6": 0
 }