test: fix integration harness lint findings

pyproject.toml

@@ -88,6 +88,11 @@ ignore = [
 
 [tool.ruff.lint.per-file-ignores]
 "__init__.py" = ["F401"]
+"tests/integration/harness.py" = [
+    "S101",
+    "S603",  # the harness drives the trusted local docker CLI with fixed argv
+    "S607",  # docker is resolved from PATH on purpose (CI and local hosts differ)
+]
 "tests/**" = [
     "S101",  # assert is the point of tests
     "S105",  # hardcoded fake tokens in fixtures