merge: testing → main (reconcile 2-week divergence)

decnet/realism/llm/impl/__init__.py

@@ -0,0 +1,6 @@
+"""Concrete LLM-backend implementations.
+
+Importers go through :func:`decnet.realism.llm.get_llm`, not these
+modules directly — same convention as :mod:`decnet.web.db.sqlite` and
+:mod:`decnet.bus.unix_client`.
+"""