feat(node_assets): add image plane geometry nodes and validation scripts

- Implemented `image_plane.py` to build the Image Plane Geometry Nodes group with customizable parameters for geometry, subdivide, and thickness.
- Created `image_plane_validation.py` to validate the functionality of the image plane, ensuring correct geometry generation and material assignment.
- Developed `material_layers.py` to construct shader node groups for image materials, including depth and normal handling.
- Authored `plane_layouts.py` to define node arrangements for image geometry assets.
- Introduced `shadeless.py` to create a shadeless shader node group that displays color without scene lighting while preserving shadows and reflections.

tests/server_runtime_test_support.py

@@ -0,0 +1,66 @@
+import importlib.util
+import sys
+import tempfile
+import time
+import unittest
+from pathlib import Path
+
+
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+
+def load_server_module():
+    server_directory = PROJECT_ROOT / "src" / "anyimage" / "server"
+    specification = importlib.util.spec_from_file_location(
+        "server",
+        server_directory / "__init__.py",
+        submodule_search_locations=[str(server_directory)],
+    )
+    module = importlib.util.module_from_spec(specification)
+    sys.modules["server"] = module
+    specification.loader.exec_module(module)
+    return module
+
+class ServerTestCase(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.server_module = load_server_module()
+        importlib.import_module("server.geometry.prediction_artifacts")
+        importlib.import_module("server.jobs.cutout")
+        from blendjob import JobServer
+        from server.model_manager import ModelManager, ModelSessionCache
+        from server.models import onnx_runtime
+
+        cls.JobServer = JobServer
+
+        cls.ModelManager, cls.ModelSessionCache = ModelManager, ModelSessionCache
+        cls.onnx_runtime = onnx_runtime
+        cls.server = cls.server_module.server
+        cls.app_module = sys.modules["server.app"]
+
+
+    def setUp(self):
+        self.jobs_temp = tempfile.TemporaryDirectory()
+        self.addCleanup(self.jobs_temp.cleanup)
+        self.storage_root = Path(self.jobs_temp.name)
+
+
+    def create_cache(self):
+        return self.ModelSessionCache()
+
+
+    def create_server(self):
+        source = self.server_module.server
+        server = self.JobServer("AnyImage Job Server", storage_root=self.storage_root)
+        server.handlers.update(source.handlers)
+        server.resource_factories.update(source.resource_factories)
+        server.bind(self.storage_root)
+        return server
+
+
+    def wait_for_job(self, context, timeout=2.0):
+        deadline = time.monotonic() + timeout
+        while time.monotonic() < deadline:
+            if context._snapshot()["state"] in {"succeeded", "failed", "cancelled"}:
+                return context._snapshot()
+            time.sleep(0.01)
+        self.fail(f"Job did not finish: {context._snapshot()}")