fix(tui): avoid gradient interpolation for non-hex colors

Author: thatkookooguy

src/tui/components/shared/GradientText.tsx

@@ -29,6 +29,10 @@ export interface GradientTextProps {
 /**
  * Generate an array of interpolated colors for gradient text
  */
+function isHexColor(color: string): boolean {
+  return /^#([a-f\d]{6})$/i.test(color);
+}
+
 function generateGradientColors(
   startColor: string,
   endColor: string,
@@ -37,6 +41,12 @@ function generateGradientColors(
   if (steps <= 0) return [];
   if (steps === 1) return [startColor];
 
+  // If we don't have hex colors (e.g. ANSI/basic palette names like "magenta"),
+  // we can't interpolate safely. Fall back to a flat color.
+  if (!isHexColor(startColor) || !isHexColor(endColor)) {
+    return Array.from({ length: steps }, () => startColor);
+  }
+
   const colors: string[] = [];
   for (let i = 0; i < steps; i++) {
     const factor = i / (steps - 1);