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/core/objects/articulated_object.py

@@ -5,11 +5,11 @@ import random
 
 import numpy as np
 from core.objects.base_object import register_object
-from omni.isaac.core.articulations.articulation import Articulation
-from omni.isaac.core.utils.stage import add_reference_to_stage
+from core.compat import Articulation
+from core.compat import add_reference_to_stage
 
 try:
-    from omni.isaac.core.materials.omni_pbr import OmniPBR  # Isaac Sim 4.1.0 / 4.2.0
+    from core.compat import OmniPBR
 except ImportError:
     from isaacsim.core.api.materials import OmniPBR  # Isaac Sim 4.5.0
 

workflows/simbox/core/objects/conveyor_object.py

@@ -1,8 +1,8 @@
 import os
 
 from core.objects.base_object import register_object
-from omni.isaac.core.prims import GeometryPrim
-from omni.isaac.core.utils.prims import create_prim
+from core.compat import GeometryPrim
+from core.compat import create_prim
 from pxr import Gf, UsdPhysics
 
 

workflows/simbox/core/objects/geometry_object.py

@@ -3,15 +3,11 @@ import os
 import random
 
 from core.objects.base_object import register_object
-from omni.isaac.core.prims import GeometryPrim
-from omni.isaac.core.utils.prims import (
-    create_prim,
-    get_prim_at_path,
-    is_prim_path_valid,
-)
+from core.compat import GeometryPrim
+from core.compat import create_prim, get_prim_at_path, is_prim_path_valid
 
 try:
-    from omni.isaac.core.materials.omni_pbr import OmniPBR  # Isaac Sim 4.1.0 / 4.2.0
+    from core.compat import OmniPBR
 except ImportError:
     from isaacsim.core.api.materials import OmniPBR  # Isaac Sim 4.5.0
 

workflows/simbox/core/objects/plane_object.py

@@ -3,12 +3,12 @@ import os
 import random
 
 from core.objects.base_object import register_object
-from omni.isaac.core.prims import XFormPrim
-from omni.isaac.core.utils.prims import is_prim_path_valid
-from omni.isaac.core.utils.stage import get_current_stage
+from core.compat import XFormPrim
+from core.compat import is_prim_path_valid
+from core.compat import get_current_stage
 
 try:
-    from omni.isaac.core.materials.omni_pbr import OmniPBR  # Isaac Sim 4.1.0 / 4.2.0
+    from core.compat import OmniPBR
 except ImportError:
     from isaacsim.core.api.materials import OmniPBR  # Isaac Sim 4.5.0
 

workflows/simbox/core/objects/rigid_object.py

@@ -3,11 +3,11 @@ import os
 import random
 
 from core.objects.base_object import register_object
-from omni.isaac.core.prims import RigidPrim
-from omni.isaac.core.utils.prims import create_prim, get_prim_at_path
+from core.compat import RigidPrim
+from core.compat import create_prim, get_prim_at_path
 
 try:
-    from omni.isaac.core.materials.omni_pbr import OmniPBR  # Isaac Sim 4.1.0 / 4.2.0
+    from core.compat import OmniPBR
 except ImportError:
     from isaacsim.core.api.materials import OmniPBR  # Isaac Sim 4.5.0
 

workflows/simbox/core/objects/shape_object.py

@@ -3,10 +3,10 @@ import os
 import random
 
 from core.objects.base_object import register_object
-from omni.isaac.core.prims import GeometryPrim
+from core.compat import GeometryPrim
 
 try:
-    from omni.isaac.core.materials.omni_pbr import OmniPBR  # Isaac Sim 4.1.0 / 4.2.0
+    from core.compat import OmniPBR
 except ImportError:
     from isaacsim.core.api.materials import OmniPBR  # Isaac Sim 4.5.0
 

workflows/simbox/core/objects/xform_object.py

@@ -3,11 +3,11 @@ import os
 import random
 
 from core.objects.base_object import register_object
-from omni.isaac.core.prims import XFormPrim
-from omni.isaac.core.utils.prims import create_prim, is_prim_path_valid
+from core.compat import XFormPrim
+from core.compat import create_prim, is_prim_path_valid
 
 try:
-    from omni.isaac.core.materials.omni_pbr import OmniPBR  # Isaac Sim 4.1.0 / 4.2.0
+    from core.compat import OmniPBR
 except ImportError:
     from isaacsim.core.api.materials import OmniPBR  # Isaac Sim 4.5.0