Show spawned agent model and effort in TUI (#14273)

- include the requested sub-agent model and reasoning effort in the
spawn begin event\n- render that metadata next to the spawned agent name
and role in the TUI transcript

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/exec/src/event_processor_with_human_output.rs

@@ -698,6 +698,7 @@ impl EventProcessor for EventProcessorWithHumanOutput {
                 call_id,
                 sender_thread_id: _,
                 prompt,
+                ..
             }) => {
                 ts_msg!(
                     self,