Integration tests for critical journeys (ctrl-c to exit, paste, interactions).

• Press control C to exit
• Press escape to cancel
• Executing shell commands
• Approving tools.
  In particular multiple tool approval case (believe there is an active flicker regressions for this due to bad interactions between changes made in core and gemini cli package).
• Ensure that tool approval UI is surfaced, has focus, and robustly handles abort edge cases.
• Integration test validating prompt input for Terminals with spurious unhandled escape sequences inserted to verify robustness in the presence of unexpected environments.