Linux - Fix interactive prompt handling during installation with curl

[ridgunn]

What changed?

• Fixed the interactive prompt not working when installing via piped execution (curl -L <url> | sh)
• Added proper /dev/tty fallback to always allow user input where available
• Removed duplicate prompt calls
• Improved handling of non-interactive environments with a clear fallback message

Works in these cases

# ✔ Interactive (TTY prompt works even when piped)
curl -L https://example.com/install.sh | sh

# ✔ Non-interactive (automation, CI, scripts)
curl -L https://example.com/install.sh | sh -s -- -y

[mjcheetham]

Nice!