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/bluesky-pds/functional/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]}"