[8/8] Add Python SDK Ruff formatting (#22021)

## Why

The Python SDK needs the same tight formatter/lint loop as the rest of
the repo: a safe Ruff autofix pass, Ruff formatting, editor save
behavior, and CI checks that catch drift. Without that loop, SDK changes
can land with formatting or import ordering that differs from what
reviewers and CI expect.

## What

- Add Ruff configuration to `sdk/python/pyproject.toml`, excluding
generated protocol code and notebooks from the normal lint/format pass.
- Update `just fmt` so it still formats Rust and also runs Python SDK
Ruff autofix and formatting.
- Add Python SDK CI steps for `ruff check` and `ruff format --check`
before pytest.
- Recommend the Ruff VS Code extension and enable Python
format/fix/organize-on-save so Cmd+S uses the same tooling.
- Apply the resulting Ruff formatting to SDK Python files, examples, and
the checked-in generated `v2_all.py` output emitted by the pinned
generator.
- Add a guard test for the `just fmt` recipe so it keeps working from
both Rust and Python SDK working directories.

## Stack

1. #21891 `[1/8]` Pin Python SDK runtime dependency
2. #21893 `[2/8]` Generate Python SDK types from pinned runtime
3. #21895 `[3/8]` Run Python SDK tests in CI
4. #21896 `[4/8]` Define Python SDK public API surface
5. #21905 `[5/8]` Rename Python SDK package to `openai-codex`
6. #21910 `[6/8]` Add high-level Python SDK approval mode
7. #22014 `[7/8]` Add Python SDK app-server integration harness
8. This PR `[8/8]` Add Python SDK Ruff formatting

## Verification

- Added `test_root_fmt_recipe_formats_rust_and_python_sdk` for the
shared format recipe.
- Ran `just fmt` after the recipe update.

---------

Co-authored-by: Codex <noreply@openai.com>

sdk/python/tests/test_app_server_run.py

@@ -3,7 +3,6 @@ from __future__ import annotations
 import asyncio
 
 import pytest
-
 from app_server_harness import (
     AppServerHarness,
     ev_assistant_message,
@@ -13,13 +12,14 @@ from app_server_harness import (
     ev_response_created,
     sse,
 )
-from openai_codex import AsyncCodex, Codex
-from openai_codex.generated.v2_all import MessagePhase
 from app_server_helpers import (
     agent_message_texts_from_items,
     assistant_message_with_phase,
 )
 
+from openai_codex import AsyncCodex, Codex
+from openai_codex.generated.v2_all import MessagePhase
+
 
 def test_sync_thread_run_uses_mock_responses(
     tmp_path,
@@ -250,9 +250,7 @@ def test_async_run_result_uses_last_unknown_phase_message(tmp_path) -> None:
             )
 
             async with AsyncCodex(config=harness.app_server_config()) as codex:
-                result = await (await codex.thread_start()).run(
-                    "case: async last unknown phase"
-                )
+                result = await (await codex.thread_start()).run("case: async last unknown phase")
 
         assert {
             "final_response": result.final_response,
@@ -288,9 +286,7 @@ def test_async_run_result_does_not_promote_commentary_only_to_final(
             )
 
             async with AsyncCodex(config=harness.app_server_config()) as codex:
-                result = await (await codex.thread_start()).run(
-                    "case: async commentary only"
-                )
+                result = await (await codex.thread_start()).run("case: async commentary only")
 
         assert {
             "final_response": result.final_response,