Add temporary chat-request logging (diagnose SwiftChat error)

lib/n8n_openai_adapter/router.ex

@@ -212,8 +212,26 @@ defmodule N8nOpenaiAdapter.Router do
     end
   end
 
+  # Temporary diagnostics: log the raw chat request (stream flag + headers) so
+  # we can see exactly what SwiftChat sends. Remove after diagnosis.
+  defp log_request(conn, data) do
+    stream = Map.get(data, "stream")
+    accept = get_req_header(conn, "accept") |> List.first()
+    content_type = get_req_header(conn, "content-type") |> List.first()
+    model = Map.get(data, "model")
+
+    IO.puts(
+      "CHAT_REQ model=#{inspect(model)} stream=#{inspect(stream)} " <>
+        "accept=#{inspect(accept)} content_type=#{inspect(content_type)} " <>
+        "body=#{Jason.encode!(data) |> String.slice(0, 500)}"
+    )
+  end
+
   defp handle_chat(conn) do
     data = conn.body_params
+    # Temporary diagnostics: log the raw chat request so we can see exactly what
+    # SwiftChat sends (stream flag, headers). Remove after diagnosis.
+    log_request(conn, data)
 
     model = Map.get(data, "model")
     messages = Map.get(data, "messages", [])