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/bluesky-pds/custom/test_describe_server.py

@@ -26,6 +26,6 @@ def test_describe_server_returns_atproto_envelope(live_app):
     # At least one of these atproto-spec fields must be present
     expected_any = ("availableUserDomains", "inviteCodeRequired", "links", "did")
     present = [k for k in expected_any if k in body]
-    assert (
-        present
-    ), f"describe-server missing all of {expected_any}; got keys: {sorted(body.keys())[:20]}"
+    assert present, (
+        f"describe-server missing all of {expected_any}; got keys: {sorted(body.keys())[:20]}"
+    )