When Anthropic models return multi-part content lists, only the first
element was used and the rest discarded. Now iterates all parts and
concatenates text blocks, preserving the full message content.
Avoid emitting spurious empty assistant messages for tool-call-only
AIMessages (common with OpenAI models where content is empty string).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
langchain_messages_to_copilotkit previously skipped creating the assistant
message when an AIMessage had tool_calls, causing missing context in chat
history on reconnect. Also adds ActionExecutionMessage type guard in
copilotkit_messages_to_langchain to prevent KeyError on non-tool messages
with parentMessageId.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jordan Ritter