chengyongru ac714803f6 fix(provider): recover trailing assistant message as user to prevent empty request
When a subagent result is injected with current_role="assistant",
_enforce_role_alternation drops the trailing assistant message, leaving
only the system prompt. Providers like Zhipu/GLM reject such requests
with error 1214 ("messages parameter invalid"). Now the last popped
assistant message is recovered as a user message when no user/tool
messages remain.
2026-04-13 12:54:39 +08:00
..