Prepare Python SDK 0.144.4 stable release (#33213)

## What changed

- Mark `openai-codex` as stable and align its versioned runtime dependency with Codex CLI `0.144.4`.
- Regenerate the Python protocol models and notification registry from that runtime, exposing the latest requests, responses, notifications, and schema fields.
- Keep `ReasoningEffort` and `ThreadSource` as enum-style APIs while accepting unknown future wire values, and omit `last_turn_id` from the flat `thread_fork` helper.

## Testing

- Cover stable SDK/runtime version matching, forward-compatible enum parsing, and generated client method signatures.

GitOrigin-RevId: eaa616bcbfca4258f11274e12e7eefaa551110b7

sdk/python/tests/test_client_rpc_methods.py

@@ -7,13 +7,19 @@ from openai_codex.generated.notification_registry import notification_turn_id
 from openai_codex.generated.v2_all import (
     AgentMessageDeltaNotification,
     ApprovalsReviewer,
+    ReasoningEffort,
+    ReasoningEffortOption,
+    ThreadForkParams,
     ThreadListParams,
     ThreadResumeResponse,
+    ThreadStartParams,
     ThreadTokenUsageUpdatedNotification,
     TurnCompletedNotification,
+    TurnStartParams,
     WarningNotification,
 )
 from openai_codex.models import Notification, UnknownNotification
+from openai_codex.types import ThreadSource
 
 ROOT = Path(__file__).resolve().parents[1]
 
@@ -31,6 +37,56 @@ def test_generated_v2_bundle_has_single_shared_plan_type_definition() -> None:
     assert source.count("class PlanType(") == 1
 
 
+def test_reasoning_effort_preserves_enum_constants_and_accepts_future_values() -> None:
+    """Known effort members and new runtime values should share the enum-style API."""
+    known_option = ReasoningEffortOption.model_validate(
+        {"description": "Balanced", "reasoningEffort": "medium"}
+    )
+    future_option = ReasoningEffortOption.model_validate(
+        {"description": "Future", "reasoningEffort": "ultra"}
+    )
+    turn_params = TurnStartParams(
+        thread_id="thread-1",
+        input=[],
+        effort=ReasoningEffort.medium,
+    )
+
+    assert {
+        "known_member": ReasoningEffort.medium.value,
+        "known_option": known_option.reasoning_effort.value,
+        "future_option": future_option.reasoning_effort.value,
+        "turn_effort": _params_dict(turn_params)["effort"],
+    } == {
+        "known_member": "medium",
+        "known_option": "medium",
+        "future_option": "ultra",
+        "turn_effort": "medium",
+    }
+
+
+def test_thread_source_preserves_enum_constants_and_accepts_future_values() -> None:
+    """Known thread sources and new runtime values should share the enum-style API."""
+    start_params = ThreadStartParams(thread_source=ThreadSource.user)
+    fork_params = ThreadForkParams(
+        thread_id="thread-1",
+        thread_source=ThreadSource("future_source"),
+    )
+
+    assert {
+        "known_member": ThreadSource.user.value,
+        "subagent_member": ThreadSource.subagent.value,
+        "memory_member": ThreadSource.memory_consolidation.value,
+        "start_source": _params_dict(start_params)["threadSource"],
+        "fork_source": _params_dict(fork_params)["threadSource"],
+    } == {
+        "known_member": "user",
+        "subagent_member": "subagent",
+        "memory_member": "memory_consolidation",
+        "start_source": "user",
+        "fork_source": "future_source",
+    }
+
+
 def test_thread_resume_response_accepts_auto_review_reviewer() -> None:
     """Generated response models should keep accepting the auto review enum value."""
     response = ThreadResumeResponse.model_validate(