lint: ruff format + one auto-fix so the push self-test is green again

`scripts/lint.sh --fix` from the pinned lint devshell: 90 Python files
reformatted (ruff format, mechanical) and one C420 (dict comprehension →
dict.fromkeys) in tests/unit/test_f211_sso_skip.py. The push self-test had
been failing at the lint stage since build 1313 (2026-08-31) on exactly
these files; nothing else changed.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FqkQq3CDmFWcQ7u1LzoyRz

tests/mattermost-lts/custom/test_create_message.py

@@ -41,9 +41,9 @@ def test_create_message_roundtrip(live_app):
         headers=auth,
         timeout=30,
     )
-    assert (
-        status in (200, 201) and isinstance(team, dict) and team.get("id")
-    ), f"team creation failed: HTTP {status}, body={team!r}"
+    assert status in (200, 201) and isinstance(team, dict) and team.get("id"), (
+        f"team creation failed: HTTP {status}, body={team!r}"
+    )
     status, chan = harness_http.http_post(
         f"{base}/channels",
         data={
@@ -55,9 +55,9 @@ def test_create_message_roundtrip(live_app):
         headers=auth,
         timeout=30,
     )
-    assert (
-        status in (200, 201) and isinstance(chan, dict) and chan.get("id")
-    ), f"channel creation failed: HTTP {status}, body={chan!r}"
+    assert status in (200, 201) and isinstance(chan, dict) and chan.get("id"), (
+        f"channel creation failed: HTTP {status}, body={chan!r}"
+    )
 
     # 4) POST a unique marker message.
     marker = f"ccci-marker-{uniq}-roundtrip"
@@ -67,13 +67,13 @@ def test_create_message_roundtrip(live_app):
         headers=auth,
         timeout=30,
     )
-    assert (
-        status in (200, 201) and isinstance(post, dict) and post.get("id")
-    ), f"post creation failed: HTTP {status}, body={post!r}"
+    assert status in (200, 201) and isinstance(post, dict) and post.get("id"), (
+        f"post creation failed: HTTP {status}, body={post!r}"
+    )
 
     # 5) Read it back by id and assert the message survived the round-trip.
     status, got = harness_http.http_get(f"{base}/posts/{post['id']}", headers=auth, timeout=30)
     assert status == 200 and isinstance(got, dict), f"read-back failed: HTTP {status}, body={got!r}"
-    assert (
-        got.get("message") == marker
-    ), f"message did not round-trip: sent {marker!r}, got {got.get('message')!r}"
+    assert got.get("message") == marker, (
+        f"message did not round-trip: sent {marker!r}, got {got.get('message')!r}"
+    )