Refresh generated Python app-server SDK types (#18862)

This is the first step in splitting the Python SDK PyPI publish work
into reviewable layers: land the generated SDK refresh by itself before
changing packaging mechanics. The next PRs will make the runtime wheel
publishable, then wire the SDK package/version pinning to that runtime.

## Summary
- Refresh generated Python app-server v2 models and notification
registry from the current schema.
- Update the public API signature expectations for the newly generated
kwargs.

## Stack
- PR 1 of 3 for the Python SDK PyPI publishing split.
- Follow-up PRs will handle runtime wheel publishing mechanics, then
SDK/package version pinning.

## Tests
- `uv run --extra dev pytest` in `sdk/python` -> 51 passed, 37 skipped.

sdk/python/tests/test_public_api_signatures.py

@@ -22,7 +22,9 @@ def _assert_no_any_annotations(fn: object) -> None:
     signature = inspect.signature(fn)
     for param in signature.parameters.values():
         if param.annotation is Any:
-            raise AssertionError(f"{fn} has public parameter typed as Any: {param.name}")
+            raise AssertionError(
+                f"{fn} has public parameter typed as Any: {param.name}"
+            )
     if signature.return_annotation is Any:
         raise AssertionError(f"{fn} has public return annotation typed as Any")
 
@@ -56,6 +58,7 @@ def test_generated_public_signatures_are_snake_case_and_typed() -> None:
             "sandbox",
             "service_name",
             "service_tier",
+            "session_start_source",
         ],
         Codex.thread_list: [
             "archived",
@@ -64,6 +67,7 @@ def test_generated_public_signatures_are_snake_case_and_typed() -> None:
             "limit",
             "model_providers",
             "search_term",
+            "sort_direction",
             "sort_key",
             "source_kinds",
         ],
@@ -131,6 +135,7 @@ def test_generated_public_signatures_are_snake_case_and_typed() -> None:
             "sandbox",
             "service_name",
             "service_tier",
+            "session_start_source",
         ],
         AsyncCodex.thread_list: [
             "archived",
@@ -139,6 +144,7 @@ def test_generated_public_signatures_are_snake_case_and_typed() -> None:
             "limit",
             "model_providers",
             "search_term",
+            "sort_direction",
             "sort_key",
             "source_kinds",
         ],
@@ -197,7 +203,9 @@ def test_generated_public_signatures_are_snake_case_and_typed() -> None:
     for fn, expected_kwargs in expected.items():
         actual = _keyword_only_names(fn)
         assert actual == expected_kwargs, f"unexpected kwargs for {fn}: {actual}"
-        assert all(name == name.lower() for name in actual), f"non snake_case kwargs in {fn}: {actual}"
+        assert all(name == name.lower() for name in actual), (
+            f"non snake_case kwargs in {fn}: {actual}"
+        )
         _assert_no_any_annotations(fn)
 
 
@@ -247,4 +255,6 @@ def test_initialize_metadata_requires_non_empty_information() -> None:
     except RuntimeError as exc:
         assert "missing required metadata" in str(exc)
     else:
-        raise AssertionError("expected RuntimeError when initialize metadata is missing")
+        raise AssertionError(
+            "expected RuntimeError when initialize metadata is missing"
+        )