Fix XR teleop: body-frame IK control for mobile chassis

Switch arm IK from world-frame to body-frame control so that
pushing the XR controller forward always moves the arm in the
robot's forward direction, regardless of chassis rotation.

Key changes:
- dual_arm_agent: convert EEF observations to body frame before
  passing to XR controller; send body-frame IK targets directly
  (removed convert_action_world_to_root)
- xr_controller: XR deltas treated as body-frame deltas (no yaw
  rotation needed — VR view tracks robot heading naturally)
- streaming: add debug frame save for stereo alignment diagnostics
- mindrobot_2i_cfg: IdealPDActuator for trunk, disabled gravity
- Author headers updated to Yutang Li, SIAT

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

source/mindbot/mindbot/tasks/manager_based/il/open_drybox/mindrobot_2i_cfg.py

@@ -21,7 +21,7 @@ from mindbot.utils.assets import MINDBOT_ASSETS_DIR
 MINDBOT_CFG = ArticulationCfg(
     spawn=sim_utils.UsdFileCfg(
         # usd_path=f"{MINDBOT_ASSETS_DIR}/robots/mindrobot_2i/mindrobot_2i.usd",
-        usd_path=f"{MINDBOT_ASSETS_DIR}/robots/mindbot_zed/mindbot.usd",
+        usd_path=f"{MINDBOT_ASSETS_DIR}/robots/mindbot_zed/mindbot_mini.usd",
         activate_contact_sensors=True,
         rigid_props=sim_utils.RigidBodyPropertiesCfg(
             disable_gravity=False,
@@ -61,7 +61,7 @@ MINDBOT_CFG = ArticulationCfg(
             # NOTE: pos z = 0.44 (base clearance) + PrismaticJoint value.
             # If you change PrismaticJoint, update pos z accordingly to avoid
             # geometry clipping that causes the robot to fall on spawn.
-            "PrismaticJoint": 0.26,
+            "PrismaticJoint": 0.4,
             "head_pitch_Joint": 0.0,
             "head_yaw_Joint": 0.0,
         },
@@ -115,8 +115,8 @@ MINDBOT_CFG = ArticulationCfg(
             joint_names_expr=["PrismaticJoint"],
             effort_limit=100.0,
             velocity_limit=0.2,
-            stiffness=10000.0,
-            damping=1000.0,
+            stiffness=100000.0,
+            damping=10000.0,
         ),
         "wheels": ImplicitActuatorCfg(
             # joint_names_expr=[".*_revolute_Joint"],