Remove detached delivery from review/start (#57667)

## What changed

`review/start` now supports only inline reviews on the supplied thread and returns that thread's id as `reviewThreadId`. Clients can omit `delivery`, send `null`, or specify `"inline"`; `"detached"` is no longer supported.

For a separate review thread, call `thread/start` followed by `review/start`. To preserve conversation history with custom review instructions, use `thread/fork` followed by `turn/start`.

Remove detached review execution and its app-server dependency on `codex-agent-extension`, and update the protocol schemas and generated clients. Preserve `ReviewDelivery.inline` as a Python enum member.

## Testing

Add a Python regression test verifying that inline review delivery parses as `ReviewDelivery.inline` and round-trips to the original JSON.

GitOrigin-RevId: ed16c5271c3315ae3afcb3ee78883ed421394b4d

sdk/python/tests/test_client_rpc_methods.py

@@ -23,6 +23,8 @@ from openai_codex.generated.v2_all import (
     PlanType,
     ReasoningEffort,
     ReasoningEffortOption,
+    ReviewDelivery,
+    ReviewStartParams,
     ThreadForkParams,
     ThreadListParams,
     ThreadQueueChangedNotification,
@@ -39,6 +41,14 @@ from openai_codex.types import ThreadSource
 ROOT = Path(__file__).resolve().parents[1]
 
 
+def test_inline_review_delivery_round_trips_as_an_enum() -> None:
+    wire = {"threadId": "thread-1", "target": {"type": "uncommittedChanges"}, "delivery": "inline"}
+    params = ReviewStartParams.model_validate(wire)
+
+    assert params.delivery is ReviewDelivery.inline
+    assert params.model_dump(mode="json", by_alias=True) == wire
+
+
 @pytest.mark.parametrize(
     ("model", "fields"),
     [