The integration tests load the real plugin module against a thin mock Cordis
context and drive the tool through a real shell into the real slopo binary. The
mock implements only the seams the plugin touches, so a wrong assumption about a
dsh service fails a test instead of producing a plugin that silently does
nothing at runtime.
Two real bugs were caught this way and are now pinned:
* renderSlopoConfig would write the embedding API key to disk if it were
handed one. It cannot now.
* --config-version was placed before the subcommand, which slopo rejects with
exit code 2. It is declared on the command, not the callback.
The end-to-end test is opt-in (DSH_SLOPO_E2E=1) because it needs a reachable
embedding backend; it indexes a real repository, embeds it, and asserts a real
duplicate cluster comes back.
