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/keycloak/recipe_meta.py

@@ -2,5 +2,7 @@
 # conftest — enrolling this recipe needs NO change to runner/harness code (D5).
 HEALTH_PATH = "/realms/master"  # 200 JSON once keycloak is up (not "/", which redirects)
 HEALTH_OK = (200,)
-DEPLOY_TIMEOUT = 900  # JVM + DB migration are slow on a 2-vCPU VM; observed 502 fallback up to ~10min
+DEPLOY_TIMEOUT = (
+    900  # JVM + DB migration are slow on a 2-vCPU VM; observed 502 fallback up to ~10min
+)
 HTTP_TIMEOUT = 900