Implement BiRefNet and HAT Sharper models with background removal capabilities

- Added validation documentation for AI model tiers.
- Introduced `background.py` for background removal logic, including inference functions for alpha and foreground extraction.
- Created `onnx_birefnet.py` to handle BiRefNet model sessions and alpha inference.
- Developed tests for background models, ensuring proper dispatch and session reuse.
- Added tests for BiRefNet ONNX model to validate alpha output and error handling for invalid values.
- Implemented model export scripts for BiRefNet and HAT Sharper, ensuring proper weight compression and licensing.
- Created `deform_sampling.py` for deformable convolution operations used in BiRefNet.
- Added utility functions for compressing ONNX weights without altering graph arithmetic.
- Introduced a reference plane node for depth field adjustments in geometry processing.

tests/anyimage/operators/test_ai_setup.py

@@ -31,7 +31,7 @@ class AiSetupTest(BlenderTestCase):
             calls,
             [
                 ("download-model", {"model": "MOGE2_VITS_NORMAL"}),
-                ("download-model", {"model": "BEN2_BASE"}),
+                ("download-model", {"model": "BIREFNET_LITE"}),
                 (
                     "download-model",
                     {"model": "REALESRGAN_GENERAL_WDN_X4V3"},
@@ -50,9 +50,9 @@ class AiSetupTest(BlenderTestCase):
         with self.assertRaisesRegex(
             RuntimeError,
             (
-                "MoGe-2 ViT-S Normal: network unavailable; "
-                "BEN2 Base: network unavailable; "
-                "Real-ESRGAN General WDN x4v3: network unavailable"
+                "Fast \\| MoGe-2 ViT-S Normal: network unavailable; "
+                "Fast \\| BiRefNet Lite: network unavailable; "
+                "Fast \\| Real-ESRGAN General WDN x4v3: network unavailable"
             ),
         ):
             self.runtime.post_install(SimpleNamespace(request=request))
@@ -61,7 +61,7 @@ class AiSetupTest(BlenderTestCase):
             calls,
             [
                 "MOGE2_VITS_NORMAL",
-                "BEN2_BASE",
+                "BIREFNET_LITE",
                 "REALESRGAN_GENERAL_WDN_X4V3",
             ],
         )
@@ -77,7 +77,7 @@ class AiSetupTest(BlenderTestCase):
             {
                 "models": [
                     "MOGE2_VITS_NORMAL",
-                    "BEN2_BASE",
+                    "BIREFNET_LITE",
                     "REALESRGAN_GENERAL_WDN_X4V3",
                 ]
             },
@@ -93,7 +93,7 @@ class AiSetupTest(BlenderTestCase):
                 "model_catalog",
                 return_value=(
                     {"key": "MOGE2_VITS_NORMAL", "ready": True},
-                    {"key": "BEN2_BASE", "ready": False},
+                    {"key": "BIREFNET_LITE", "ready": False},
                     {
                         "key": "REALESRGAN_GENERAL_WDN_X4V3",
                         "ready": True,
@@ -103,7 +103,7 @@ class AiSetupTest(BlenderTestCase):
         ):
             status = properties.ai_status()
         self.assertTrue(status["environment_ready"])
-        self.assertEqual(status["missing_models"], ("BEN2_BASE",))
+        self.assertEqual(status["missing_models"], ("BIREFNET_LITE",))
         self.assertFalse(status["ready"])
         self.assertEqual(properties.ai_setup_label(status), "Download Required Models…")
 
@@ -114,7 +114,7 @@ class AiSetupTest(BlenderTestCase):
                 "model_catalog",
                 return_value=tuple(
                     {"key": key, "ready": True}
-                    for key in properties.REQUIRED_MODEL_KEYS
+                    for key in properties.shared_model_catalog.DEFAULT_MODEL_KEYS
                 ),
             ),
         ):
@@ -148,7 +148,7 @@ class AiSetupTest(BlenderTestCase):
                 "ai_status",
                 return_value={
                     "environment_ready": False,
-                    "missing_models": ("MOGE2_VITS_NORMAL", "BEN2_BASE"),
+                    "missing_models": ("MOGE2_VITS_NORMAL", "BIREFNET_LITE"),
                     "ready": False,
                 },
             ):
@@ -159,7 +159,7 @@ class AiSetupTest(BlenderTestCase):
                 "ai_status",
                 return_value={
                     "environment_ready": True,
-                    "missing_models": ("BEN2_BASE",),
+                    "missing_models": ("BIREFNET_LITE",),
                     "ready": False,
                 },
             ):
@@ -185,13 +185,14 @@ class AiSetupTest(BlenderTestCase):
         with tempfile.TemporaryDirectory() as directory:
             root = Path(directory)
             moge = root / "models" / "moge-2-vits-normal-onnx"
-            ben2 = root / "models" / "BEN2-ONNX" / "onnx"
+            lite = root / "models" / "birefnet-lite"
             wdn = root / "models" / "realesr-general-wdn-x4v3"
             moge.mkdir(parents=True)
-            ben2.mkdir(parents=True)
+            lite.mkdir(parents=True)
             wdn.mkdir(parents=True)
             (moge / "model.onnx").touch()
-            (ben2 / "model_fp16.onnx").touch()
+            (lite / "model.onnx").touch()
+            (lite / "LICENSE.txt").touch()
             (wdn / "realesr-general-wdn-x4v3.onnx").touch()
 
             with (