Add tools and tests for AnyImage model management and documentation

- Implement sync_models.py for preparing and uploading ONNX artifacts.
- Create build_node.py for building and validating Blender scripts.
- Add docs.py for building and previewing documentation with Mike or MkDocs.
- Introduce model_exports.py for exporting PyTorch models to ONNX format.
- Develop pack.py for packaging the project with dependencies for different platforms.
- Add test_sync_models.py to validate sync_models functionality.
- Add test_tool_commands.py to ensure repository tools have correct command scripts.
- Initialize tools package with __init__.py.

tests/test_extension_manifest.py

@@ -0,0 +1,25 @@
+import tomllib
+import unittest
+from pathlib import Path
+
+
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+MANIFEST_PATH = PROJECT_ROOT / "src" / "anyimage" / "blender_manifest.toml"
+
+
+class ExtensionManifestTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.manifest = tomllib.loads(MANIFEST_PATH.read_text(encoding="utf-8"))
+
+    def test_declares_modern_extension_metadata(self):
+        self.assertEqual(self.manifest["schema_version"], "1.0.0")
+        self.assertEqual(self.manifest["id"], "anyimage")
+        self.assertEqual(self.manifest["type"], "add-on")
+        self.assertNotIn("bl_info", self.manifest)
+
+    def test_declares_required_environment_permissions(self):
+        self.assertEqual(
+            set(self.manifest["permissions"]),
+            {"network", "files"},
+        )