feat: migrate omni.isaac.* imports to isaacsim.* via compat layer

- Add core/compat.py: compatibility module with try/except imports
  supporting both IS 4.x (omni.isaac.*) and IS 5.x+ (isaacsim.*)
- Migrate 152 imports across 47 files from direct omni.isaac.* to core.compat
- Handle class renames: RigidPrim→SingleRigidPrim, GeometryPrim→SingleGeometryPrim,
  XFormPrim→SingleXFormPrim, Articulation→SingleArticulation (aliased for compatibility)
- Add migerate/migrate_imports.py: automated migration script for future use
- Leave debug_draw and env_loader try/except imports as-is

This eliminates ~100 deprecation warnings from our code on IS 5.0,
and future-proofs for IS 6.x when old APIs may be removed.

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

workflows/simbox_dual_workflow.py

@@ -10,11 +10,8 @@ from datetime import datetime
 
 import numpy as np
 import yaml
-from omni.isaac.core.utils.prims import get_prim_at_path
-from omni.isaac.core.utils.transformations import (
-    get_relative_transform,
-    pose_from_tf_matrix,
-)
+from core.compat import get_prim_at_path
+from core.compat import get_relative_transform, pose_from_tf_matrix
 from omni.physx import acquire_physx_interface
 from tqdm import tqdm
 from yaml import Loader
@@ -73,7 +70,7 @@ class SimBoxDualWorkFlow(NimbusWorkFlow):
 
     def reset(self, need_preload: bool = True):
         # source code noted this as debug, so it could be removed later
-        from omni.isaac.core.utils.viewports import set_camera_view
+        from core.compat import set_camera_view
 
         set_camera_view(eye=[1.3, 0.7, 2.7], target=[0.0, 0, 1.5], camera_prim_path="/OmniverseKit_Persp")
         # Modify config