image-gen-event/client_processing (#13512)

enabling client-side to process with image-generation capabilities
(setting app-server)

codex-rs/mcp-server/src/codex_tool_runner.rs

@@ -352,6 +352,8 @@ async fn run_codex_tool_session_inner(
                     | EventMsg::UserMessage(_)
                     | EventMsg::ShutdownComplete
                     | EventMsg::ViewImageToolCall(_)
+                    | EventMsg::ImageGenerationBegin(_)
+                    | EventMsg::ImageGenerationEnd(_)
                     | EventMsg::RawResponseItem(_)
                     | EventMsg::EnteredReviewMode(_)
                     | EventMsg::ItemStarted(_)