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-drive/setup_custom_tests.sh

@@ -29,7 +29,7 @@ docker service scale --detach "${STACK}_minio-createbuckets=1" >/dev/null 2>&1 |
 for i in $(seq 1 30); do
   MC_CID=$(docker ps -q -f "name=${STACK}_minio.1" | head -1)
   if [ -n "$MC_CID" ] && docker exec "$MC_CID" sh -c \
-       'mc alias set _c http://localhost:9000 "$(cat /run/secrets/minio_ru)" "$(cat /run/secrets/minio_rp)" >/dev/null 2>&1 && mc ls _c/drive-media-storage >/dev/null 2>&1'; then
+    'mc alias set _c http://localhost:9000 "$(cat /run/secrets/minio_ru)" "$(cat /run/secrets/minio_rp)" >/dev/null 2>&1 && mc ls _c/drive-media-storage >/dev/null 2>&1'; then
     echo "  setup: bucket drive-media-storage present after ${i} poll(s)"
     break
   fi