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/scenes/MapScene.js

@@ -1,4 +1,5 @@
 import Phaser from 'phaser';
+import { fontSize } from '../utils/responsive.js';
 
 export default class MapScene extends Phaser.Scene {
     constructor() {
@@ -16,7 +17,7 @@ export default class MapScene extends Phaser.Scene {
 
         // Title
         this.add.text(400, 30, 'Navigation Map - Choose Your Destination', {
-            fontSize: '24px',
+            fontSize: fontSize(24),
             fill: '#fff',
             fontStyle: 'bold'
         }).setOrigin(0.5);
@@ -57,7 +58,7 @@ export default class MapScene extends Phaser.Scene {
         closeButton.setStrokeStyle(2, 0xffffff);
 
         const closeText = this.add.text(750, 50, 'CLOSE', {
-            fontSize: '16px',
+            fontSize: fontSize(16),
             fill: '#fff'
         }).setOrigin(0.5);
 
@@ -102,7 +103,7 @@ export default class MapScene extends Phaser.Scene {
 
         // Location name
         const text = this.add.text(x, y, name, {
-            fontSize: '12px',
+            fontSize: fontSize(12),
             fill: '#fff',
             fontStyle: 'bold',
             align: 'center'
@@ -136,7 +137,7 @@ export default class MapScene extends Phaser.Scene {
         panel.setStrokeStyle(2, 0xffffff);
 
         this.inventoryText = this.add.text(20, 40, '', {
-            fontSize: '14px',
+            fontSize: fontSize(14),
             fill: '#fff'
         });
 
@@ -163,7 +164,7 @@ export default class MapScene extends Phaser.Scene {
         this.messageBox.setStrokeStyle(2, 0xcccccc);
 
         this.messageText = this.add.text(400, 560, '', {
-            fontSize: '16px',
+            fontSize: fontSize(16),
             fill: '#fff',
             wordWrap: { width: 740 },
             align: 'center'