Python: Add declarative workflow runtime (#2815)

* Further support for declarative python workflows

* Add tests. Clean up for typing and formatting

* Improvements and cleanup

* Typing cleanup. Improve docstrings

* Proper code in docstrings

* Fix malformed code-block directive in docstring

* Remove dead links

* PR feedback

* Address PR feedback

* Address PR feedback

* Remove sl

* Update devui frontend

* More cleanup

* Fix uv lock

* Skip Py 3.14 tests as powerfx doesn't support it

* Fix mypy error

* Fix for tool calls

* Removed stale docstring

* Fix lint

* Standardize on .NET namespaces. Revert DevUI changes (bring in later)

* Implement remaining items for Python declarative support to match dotnet

python/packages/declarative/tests/conftest.py

@@ -0,0 +1,20 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""Pytest configuration for declarative tests."""
+
+import sys
+
+import pytest
+
+# Skip all tests in this directory on Python 3.14+ because powerfx doesn't support it yet
+if sys.version_info >= (3, 14):
+    collect_ignore_glob = ["test_*.py"]
+
+
+def pytest_collection_modifyitems(config: pytest.Config, items: list[pytest.Item]) -> None:
+    """Skip all declarative tests on Python 3.14+ due to powerfx incompatibility."""
+    if sys.version_info >= (3, 14):
+        skip_marker = pytest.mark.skip(reason="powerfx does not support Python 3.14+")
+        for item in items:
+            if "declarative" in str(item.fspath):
+                item.add_marker(skip_marker)