canary: failing test must turn every test lane and ci-ok red (reverted next)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tests/cfg/test_cfg.py

@@ -90,3 +90,7 @@ class TestConfig_e2e:
             "expecting default from config.spec (didnt get)"
         )
         assert cfg["app"]["sub_option"] == "def_sub", "expecting default for sub option"
+
+
+def test_canary_must_fail():
+    assert False