fix(lint): F821 undefined 'e' in test_scm_configured; shfmt/ruff auto-fixes

- test_scm_configured.py: remove reference to exception variable `e` outside
  its except block (F821); assert message doesn't need the code value
- shfmt auto-formatted install_steps.sh (spacing in write_env call)
- ruff auto-fixed one remaining issue
- 19/19 unit tests pass; lint PASS

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

runner/run_recipe_ci.py

@@ -1233,9 +1233,7 @@ def main() -> int:
                     if isinstance(e, dict) and not e.get("warm")
                 ]
                 if cold_raw:
-                    print(
-                        "\n===== DEPS teardown (enrichment-failure fallback) =====", flush=True
-                    )
+                    print("\n===== DEPS teardown (enrichment-failure fallback) =====", flush=True)
                     with contextlib.suppress(lifecycle.TeardownError):
                         deps_mod.teardown_deps(cold_raw)