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/n8n/test_install.py

@@ -8,7 +8,8 @@ import os
 import sys
 
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "runner"))
-from harness import browser as harness_browser, generic, lifecycle  # noqa: E402
+from harness import browser as harness_browser  # noqa: E402
+from harness import generic, lifecycle
 
 
 def test_serving_and_editor(live_app, meta):
@@ -33,9 +34,10 @@ def test_serving_and_editor(live_app, meta):
             ctx = browser.new_context(ignore_https_errors=True)
             page = ctx.new_page()
             resp = harness_browser.goto_with_retry(page, url, accept_statuses=(200, 304))
-            assert resp is not None and resp.status in (200, 304), (
-                f"page status {resp and resp.status}"
-            )
+            assert resp is not None and resp.status in (
+                200,
+                304,
+            ), f"page status {resp and resp.status}"
             body = page.content().lower()
             assert "n8n" in body or "<html" in body, "no n8n content served"
         finally: