tui: show queued messages during response stream (#5540)

This fixes an issue where messages sent during the final response stream
would seem to disappear, because the "queued messages" UI wasn't shown
during streaming.

codex-rs/tui/src/chatwidget/tests.rs

@@ -38,6 +38,7 @@ use codex_core::protocol::UndoCompletedEvent;
 use codex_core::protocol::UndoStartedEvent;
 use codex_core::protocol::ViewImageToolCallEvent;
 use codex_protocol::ConversationId;
+use codex_protocol::parse_command::ParsedCommand;
 use codex_protocol::plan_tool::PlanItemArg;
 use codex_protocol::plan_tool::StepStatus;
 use codex_protocol::plan_tool::UpdatePlanArgs;