style: repo-wide lint pass — make the lint gate green again

Push builds have been RED on the lint step since ~build 209 from accumulated
formatting drift. This is the mechanical cleanup: ruff format + ruff --fix
(UP038 isinstance unions, SIM105 contextlib.suppress, UP031 f-strings, SIM115
tempfile context manager), shfmt -i 2 -ci, nixpkgs-fmt/statix/deadnix (merged
attrsets, dropped unused lib args), yamllint, and shell quoting fixes in
tests/lasuite-docs/setup_custom_tests.sh. No behaviour changes intended;
lint: PASS, unit tests: 138 passed.

tests/lasuite-docs/functional/test_auth_required.py

@@ -28,9 +28,7 @@ def test_users_me_requires_auth(live_app):
     url = f"https://{live_app}/api/v1.0/users/me/"
     # Retry with broad acceptance: any 4xx (or specific 401) indicates the route exists + auth is
     # required. Reject 200 (anonymous access) and 5xx (broken backend).
-    status, _ = harness_http.retry_http_get(
-        url, expect_status=(401, 403), max_wait=60, interval=3
-    )
+    status, _ = harness_http.retry_http_get(url, expect_status=(401, 403), max_wait=60, interval=3)
     assert status in (401, 403), (
         f"GET {url} returned {status}, expected 401 (auth required). "
         f"200 = anonymous access leaked; 404 = route missing; 5xx = backend broken."