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_node_asset_launcher.py

@@ -0,0 +1,72 @@
+import importlib.util
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+
+
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+SCRIPT_PATH = PROJECT_ROOT / "tools" / "build_node.py"
+
+
+def load_launcher():
+    specification = importlib.util.spec_from_file_location(
+        "node_asset_launcher",
+        SCRIPT_PATH,
+    )
+    module = importlib.util.module_from_spec(specification)
+    specification.loader.exec_module(module)
+    return module
+
+
+def test_blender_path_prefers_explicit_path(tmp_path):
+    launcher = load_launcher()
+    executable = tmp_path / "blender"
+    executable.touch()
+
+    with patch.dict("os.environ", {"BLENDER_BIN": "ignored"}):
+        assert launcher.blender_path(executable) == executable
+
+
+def test_blender_path_reads_environment(tmp_path):
+    launcher = load_launcher()
+    executable = tmp_path / "blender"
+    executable.touch()
+
+    with patch.dict("os.environ", {"BLENDER_BIN": str(executable)}):
+        assert launcher.blender_path() == executable
+
+
+def test_blender_path_reads_project_dotenv(tmp_path):
+    launcher = load_launcher()
+    executable = tmp_path / "Blender 4.5" / "blender.exe"
+    executable.parent.mkdir()
+    executable.touch()
+    env_path = tmp_path / ".env"
+    env_path.write_text(
+        f'BLENDER_BIN="{executable}"\n',
+        encoding="utf-8",
+    )
+
+    with patch.dict("os.environ", {}, clear=True), patch.object(
+        launcher,
+        "PROJECT_ROOT",
+        tmp_path,
+    ):
+        assert launcher.blender_path() == executable
+
+
+def test_blender_path_reports_missing_configuration(tmp_path):
+    launcher = load_launcher()
+
+    with patch.dict("os.environ", {}, clear=True), patch.object(
+        launcher.shutil,
+        "which",
+        return_value=None,
+    ), patch.object(
+        launcher,
+        "PROJECT_ROOT",
+        tmp_path,
+    ):
+        with pytest.raises(RuntimeError, match="Blender not found"):
+            launcher.blender_path()