truncatePad function
Truncates text to width and pads to fill remaining space.
Combines truncation and padding for fixed-width column rendering.
Example:
truncatePad('Hello World', 8); // 'Hello W…'
truncatePad('Hi', 8); // 'Hi '
Implementation
String truncatePad(String text, int width) {
if (text.length <= width) return padRight(text, width);
if (width <= 1) return text.substring(0, width);
return '${text.substring(0, width - 1)}…';
}