feat: add Deep Sea alternative hunting area

- Add Deep Sea location to navigation map
- Create DeepSeaHuntingScene with dark atmosphere
- Add deep ocean transition visuals
- Bioluminescent particles and giant shadows

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

src/main.js

@@ -4,6 +4,7 @@ import ShipDeckScene from './scenes/ShipDeckScene.js';
 import MapScene from './scenes/MapScene.js';
 import TransitionScene from './scenes/TransitionScene.js';
 import HuntingScene from './scenes/HuntingScene.js';
+import DeepSeaHuntingScene from './scenes/DeepSeaHuntingScene.js';
 
 const config = {
     type: Phaser.AUTO,
@@ -11,7 +12,7 @@ const config = {
     height: 600,
     parent: 'game-container',
     backgroundColor: '#2d5f8e',
-    scene: [IntroScene, ShipDeckScene, MapScene, TransitionScene, HuntingScene],
+    scene: [IntroScene, ShipDeckScene, MapScene, TransitionScene, HuntingScene, DeepSeaHuntingScene],
     physics: {
         default: 'arcade',
         arcade: {