feat: add responsive font sizing for mobile

- Add src/utils/responsive.js with fontSize() helper
- Mobile fonts scale 1.4x for better readability
- Update all scenes to use responsive font sizes
- Update deploy-k8s.sh with full deployment steps

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/utils/responsive.js

@@ -0,0 +1,26 @@
+// Responsive utilities for mobile-friendly text sizing
+
+const isMobile = /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent);
+
+// Font size multiplier for mobile devices
+const MOBILE_SCALE = 1.4;
+
+/**
+ * Get responsive font size - larger on mobile for better readability
+ * @param {number} baseSize - Base font size in pixels
+ * @returns {string} Font size string with 'px' suffix
+ */
+export function fontSize(baseSize) {
+    const size = isMobile ? Math.round(baseSize * MOBILE_SCALE) : baseSize;
+    return `${size}px`;
+}
+
+/**
+ * Check if running on mobile device
+ * @returns {boolean}
+ */
+export function checkMobile() {
+    return isMobile;
+}
+
+export default { fontSize, checkMobile, isMobile };