Function tx_confirm 

pub fn tx_confirm() -> bool

Prompt the user to confirm a transmit action.

Returns true when the caller may proceed:

• CONFIRM_TX is false — confirmation globally disabled.
• The user typed y or yes (case-insensitive).

Returns false when the caller must abort:

• Script mode is active and confirmation is required.
• The user typed anything else, including blank lines.
• Reading from stdin failed.

In the abort path the function prints an explanatory line via plain println! (so the message is not suppressed by the history buffer or the quiet flag — confirmation is always loud).