fix(tui): normalize tabs for terminal output (#6697)

packages/tui/src/utils.ts

@@ -274,14 +274,35 @@ export function visibleWidth(str: string): number {
  * Normalize text for terminal output without changing logical editor content.
  * Some terminals render precomposed Thai/Lao AM vowels inconsistently during
  * differential repaint. Their compatibility decompositions have the same cell
- * width but avoid stale-cell artifacts in terminal renderers.
+ * width but avoid stale-cell artifacts in terminal renderers. Visible tabs are
+ * expanded to the fixed width used by layout so terminal tab stops cannot wrap
+ * a logical line, while tabs inside terminal string sequences stay untouched.
  */
 const THAI_LAO_AM_REGEX = /[\u0e33\u0eb3]/;
 const THAI_LAO_AM_GLOBAL_REGEX = /[\u0e33\u0eb3]/g;
 
 export function normalizeTerminalOutput(str: string): string {
-	if (!THAI_LAO_AM_REGEX.test(str)) return str;
-	return str.replace(THAI_LAO_AM_GLOBAL_REGEX, (char) => (char === "\u0e33" ? "\u0e4d\u0e32" : "\u0ecd\u0eb2"));
+	let normalized = str;
+	if (THAI_LAO_AM_REGEX.test(normalized)) {
+		normalized = normalized.replace(THAI_LAO_AM_GLOBAL_REGEX, (char) =>
+			char === "\u0e33" ? "\u0e4d\u0e32" : "\u0ecd\u0eb2",
+		);
+	}
+	if (!normalized.includes("\t")) return normalized;
+
+	let result = "";
+	let i = 0;
+	while (i < normalized.length) {
+		const ansi = extractAnsiCode(normalized, i);
+		if (ansi) {
+			result += ansi.code;
+			i += ansi.length;
+			continue;
+		}
+		result += normalized[i] === "\t" ? "   " : normalized[i];
+		i++;
+	}
+	return result;
 }
 
 /**