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/ghost/test_restore.py

@@ -22,7 +22,7 @@ from harness import lifecycle  # noqa: E402
 
 
 def _mysql(domain, sql):
-    cmd = 'MYSQL_PWD="$(cat /run/secrets/db_password)" ' f'mysql -u root -N -s ghost -e "{sql}"'
+    cmd = f'MYSQL_PWD="$(cat /run/secrets/db_password)" mysql -u root -N -s ghost -e "{sql}"'
     return lifecycle.exec_in_app(domain, ["sh", "-c", cmd], service="db").strip()