fix: strip all ANSI escape sequences in terminal command output

[OmarAlaaeldein]

This PR fixes TUI display and scroll corruption caused by VT/ANSI control sequences in captured terminal-command output.

• Switches the bounded output buffer from stripColors to the existing stripAnsi utility, so cursor movement, alternate-screen, and other control sequences cannot reach the TUI.
• Leaves child-process TERM and SUDO_PROMPT unchanged.
• Preserves carriage returns rather than removing them unconditionally.
• Adds regression coverage for cursor-control sequences.