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/custom-html/custom/test_content_type_header.py

@@ -53,9 +53,9 @@ def test_content_type_html_and_txt(live_app):
     ct_txt = h_txt.get("content-type", "")
 
     # nginx default: "text/html" for .html and "text/plain" for .txt (may include "; charset=utf-8")
-    assert ct_html.startswith(
-        "text/html"
-    ), f"{html_name} Content-Type={ct_html!r}, expected text/html (nginx MIME config broken?)"
-    assert ct_txt.startswith(
-        "text/plain"
-    ), f"{txt_name} Content-Type={ct_txt!r}, expected text/plain (nginx MIME config broken?)"
+    assert ct_html.startswith("text/html"), (
+        f"{html_name} Content-Type={ct_html!r}, expected text/html (nginx MIME config broken?)"
+    )
+    assert ct_txt.startswith("text/plain"), (
+        f"{txt_name} Content-Type={ct_txt!r}, expected text/plain (nginx MIME config broken?)"
+    )

tests/custom-html/test_backup.py

@@ -16,6 +16,6 @@ MARKER_PATH = "/usr/share/nginx/html/ci-marker.txt"
 
 
 def test_backup_captures_state(live_app):
-    assert (
-        lifecycle.exec_in_app(live_app, ["cat", MARKER_PATH]).strip() == "original"
-    ), "the seeded state was not present at backup time"
+    assert lifecycle.exec_in_app(live_app, ["cat", MARKER_PATH]).strip() == "original", (
+        "the seeded state was not present at backup time"
+    )

tests/custom-html/test_restore.py

@@ -17,6 +17,6 @@ MARKER_PATH = "/usr/share/nginx/html/ci-marker.txt"
 
 def test_restore_returns_state(live_app):
     restored = lifecycle.exec_in_app(live_app, ["cat", MARKER_PATH]).strip()
-    assert (
-        restored == "original"
-    ), f"restore did not return the pre-mutation (backed-up) state: got {restored!r}"
+    assert restored == "original", (
+        f"restore did not return the pre-mutation (backed-up) state: got {restored!r}"
+    )

tests/custom-html/test_upgrade.py

@@ -16,6 +16,6 @@ MARKER_PATH = "/usr/share/nginx/html/ci-marker.txt"
 
 def test_upgrade_preserves_data(live_app):
     # the marker seeded by ops.pre_upgrade (before the harness upgraded) is still served
-    assert (
-        lifecycle.http_fetch(live_app, "/ci-marker.txt")[1].strip() == "upgrade-survives"
-    ), "data did not survive the upgrade"
+    assert lifecycle.http_fetch(live_app, "/ci-marker.txt")[1].strip() == "upgrade-survives", (
+        "data did not survive the upgrade"
+    )