fix(core): remove synchronous I/O from shell tool critical path#28397

Daksh7785 wants to merge 2 commits into

google-gemini:maingoogle-gemini/gemini-cli:mainfrom

Daksh7785:fix/ui-stutter-sync-ioDaksh7785/gemini-cli:fix/ui-stutter-sync-ioCopy head branch name to clipboard