fix: restore TTY cleanup for stream interrupts

[luyua9]

Summary

Fix the streaming interrupt key path in readData():

• register readline keypress events before listening for q / escape,
• only enable raw mode when stdin is a TTY,
• remove the keypress listener, restore raw mode, and close readline in finally when the stream exits.

Without readline.emitKeypressEvents(), the keypress listener is not reliably wired for raw stdin, so the documented stop keys can fail while the terminal is left in raw mode after early stream exit.

Validation

• git diff --check
• npm run typecheck -- --pretty false could not run in this clean checkout because dependencies are not installed (Cannot find module 'cleye', openai, @types/node, etc.).