Fix terminal paste and exit UX

[0xCheetah1]

Summary

• Add bracketed-paste handling for the Ink prompt so large multiline pastes are preserved and shown as an atomic [Pasted ~N lines] block.
• Fix prompt navigation and editing around pasted blocks, including Home/End and Backspace/Delete behavior.
• Improve exit behavior with double-Ctrl+C confirmation, reliable terminal cleanup, and resume hints only for saved sessions.

Testing

• npm run build