[NOT-787] Default session replacement prompt to no

[leo-notte]

Summary

• default the existing-session replacement prompt to no
• preserve the existing session on Enter, invalid input, or non-interactive EOF
• continue allowing explicit y/yes and --yes to stop the existing session
• cover safe defaults and EOF behavior in tests

Testing

• go test ./internal/cmd -count=1

Linear: NOT-787 https://linear.app/nottelabsinc/issue/NOT-787/notte-cli-pr-65-default-session-replacement-prompt-to-no

[greptile-apps]

Greptile Summary

This PR makes replacement of an active session opt-in, preserving the existing session when the prompt receives Enter, invalid input, or EOF.

• Changes the prompt default from [Y/n] to [y/N].
• Accepts only explicit y or yes responses.
• Adds unit-test coverage for the new default, invalid input, and non-interactive EOF.

Confidence Score: 5/5

The PR appears safe to merge with no actionable defects identified.

The implementation consistently changes the displayed default and response parsing, while tests cover the newly specified safe-default and EOF behavior.

Important Files Changed

Filename	Overview
internal/cmd/confirm.go	Safely changes active-session replacement confirmation to require explicit affirmative input while preserving the --yes bypass.
internal/cmd/confirm_test.go	Updates prompt expectations and covers affirmative, negative, empty, invalid, and EOF inputs.

_{Reviews (1): Last reviewed commit: "Default session replacement prompt to no" | Re-trigger Greptile}