reviewer fix

src/ai_generators/blog_flow.py

@@ -91,7 +91,19 @@ class BlogFlow(Flow[BlogFlowState]):
 
     @staticmethod
     def _get_chroma_client() -> "chromadb.HttpClient":
-        import chromadb
+        # Lazily import chromadb here rather than at module level.
+        # chromadb unconditionally loads hnswlib (a native C++ library
+        # compiled with AVX instructions) even when using HttpClient
+        # to talk to an external ChromaDB server.  Deferring the import
+        # avoids "Illegal instruction" (SIGILL) crashes in environments
+        # that lack AVX support (e.g. act, older CI runners).
+        try:
+            import chromadb
+        except ImportError as exc:
+            raise RuntimeError(
+                "chromadb is required for the editor phase but could not be "
+                f"imported: {exc}"
+            ) from exc
 
         chroma_port = int(os.environ["CHROMA_PORT"])
         return chromadb.HttpClient(host=os.environ["CHROMA_HOST"], port=chroma_port)