fix(prompts): properly calculate multiselect row padding on narrow terminals

This corrects a terminal rendering bug in the MultiSelectPrompt (Issue #116).
Previously, terminal row padding calculations contained two offsetting errors:
1. \	itleLineCount\ was overestimating by 1 due to trailing newlines.
2. \ooterLineCount\ was underestimating on narrow terminals because the footer string wasn't properly wrapped.

When the terminal filled up, this offset math caused the \limitOptions\ slicing window to miscalculate available space by 1 row, causing the prompt to overflow the terminal and visually overwrite itself on redraw.

This fix correctly evaluates both bounds using \wrapTextWithPrefix\ and ensures small terminals gracefully constrain multiselect options.

Signed-off-by: Harshal Patel <hp842484@gmail.com>

Author: HarshalPatel1972

.changeset/multiselect-overflow-fix.md

@@ -0,0 +1,5 @@
+---
+'@clack/prompts': patch
+---
+
+fix: correctly calculate multiselect layout row padding on narrow terminals to prevent option text overflow and visual overwriting

packages/prompts/src/multi-select.ts

@@ -170,8 +170,9 @@ export const multiselect = <Value>(opts: MultiSelectOptions<Value>) => {
 						)
 						.join('\n');
 					// Calculate rowPadding: title lines + footer lines (error message + trailing newline)
-					const titleLineCount = title.split('\n').length;
-					const footerLineCount = footer.split('\n').length + 1; // footer + trailing newline
+					const titleLineCount = title.split('\n').length - 1;
+					const wrappedFooter = wrapTextWithPrefix(opts.output, footer, '');
+					const footerLineCount = wrappedFooter.split('\n').length + 1; // footer + trailing newline
 					return `${title}${prefix}${limitOptions({
 						output: opts.output,
 						options: this.options,
@@ -184,14 +185,15 @@ export const multiselect = <Value>(opts: MultiSelectOptions<Value>) => {
 				}
 				default: {
 					const prefix = hasGuide ? `${styleText('cyan', S_BAR)}  ` : '';
-					const titleLineCount = title.split('\n').length;
+					const titleLineCount = title.split('\n').length - 1;
 					const footerLines = showInstructions
 						? formatInstructionFooter(MULTISELECT_INSTRUCTIONS, hasGuide)
 						: hasGuide
 							? [styleText('cyan', S_BAR_END)]
 							: [];
 					const footerText = footerLines.join('\n');
-					const footerLineCount = footerLines.length + 1;
+					const wrappedFooter = wrapTextWithPrefix(opts.output, footerText, '');
+					const footerLineCount = wrappedFooter.split('\n').length + 1;
 					return `${title}${prefix}${limitOptions({
 						output: opts.output,
 						options: this.options,