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/functional/test_minio_storage.py

@@ -29,8 +29,8 @@ BUCKET = "drive-media-storage"
 def _mc(domain: str, script: str) -> str:
     """Run an `mc` shell script inside the minio container (root creds from /run/secrets)."""
     prelude = (
-        'set -e; '
-        'U=$(cat /run/secrets/minio_ru); P=$(cat /run/secrets/minio_rp); '
+        "set -e; "
+        "U=$(cat /run/secrets/minio_ru); P=$(cat /run/secrets/minio_rp); "
         'mc alias set ccci http://localhost:9000 "$U" "$P" >/dev/null 2>&1; '
     )
     return lifecycle.exec_in_app(domain, ["sh", "-c", prelude + script], service="minio")
@@ -49,13 +49,13 @@ def test_minio_bucket_present_and_object_roundtrip(live_app):
         domain,
         # upload via stdin; list the object; read it back (tagged); then delete.
         f'printf %s "{marker}" | mc pipe ccci/{BUCKET}/{key} >/dev/null 2>&1; '
-        f'mc ls ccci/{BUCKET}/{key}; '
+        f"mc ls ccci/{BUCKET}/{key}; "
         f'echo "READBACK:$(mc cat ccci/{BUCKET}/{key})"; '
-        f'mc rm ccci/{BUCKET}/{key} >/dev/null 2>&1',
+        f"mc rm ccci/{BUCKET}/{key} >/dev/null 2>&1",
     )
 
     # The object was listed (its key appears) and its content round-tripped intact.
     assert f"{marker}.txt" in out, f"uploaded object not listed in bucket: {out!r}"
-    assert f"READBACK:{marker}" in out, (
-        f"object content did not round-trip through MinIO; got: {out!r}"
-    )
+    assert (
+        f"READBACK:{marker}" in out
+    ), f"object content did not round-trip through MinIO; got: {out!r}"