[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_public_api_runtime_behavior.py

@@ -7,13 +7,13 @@ from typing import Any
 import pytest
 
 import openai_codex.api as public_api_module
-from openai_codex.generated.v2_all import TurnStartParams
-from openai_codex.models import InitializeResponse
 from openai_codex.api import (
     ApprovalMode,
     AsyncCodex,
     Codex,
 )
+from openai_codex.generated.v2_all import TurnStartParams
+from openai_codex.models import InitializeResponse
 
 ROOT = Path(__file__).resolve().parents[1]
 
@@ -129,9 +129,7 @@ def test_async_codex_initializes_only_once_under_concurrency() -> None:
 
 def _approval_mode_turn_params(approval_mode: ApprovalMode) -> TurnStartParams:
     """Build real generated turn params from one public approval mode."""
-    approval_policy, approvals_reviewer = public_api_module._approval_mode_settings(
-        approval_mode
-    )
+    approval_policy, approvals_reviewer = public_api_module._approval_mode_settings(approval_mode)
     return TurnStartParams(
         thread_id="thread-1",
         input=[],