Decouple travel and cooking fuel mechanics

- Travel is now free (no fuel cost for sailing between locations)
- Fuel is only consumed for cooking whale oil (2 fuel per whale)
- Updated TransitionScene to show "The wind carries your sails..." when no fuel cost
- Removed fuel checks from MapScene travel methods
- Added fuel validation in HuntingScene - can't process whales without fuel
- This sets up the penguin burning mechanic for when cooking fuel runs low

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/scenes/MapScene.js

@@ -155,43 +155,31 @@ export default class MapScene extends Phaser.Scene {
     }
 
     goToHunting() {
-        if (this.inventory.fuel < 20) {
-            this.showMessage('Not enough fuel to reach the hunting grounds! You need at least 20 units.');
-            return;
-        }
-        // Go to transition scene, then to hunting scene
+        // Sailing is free - fuel is only for cooking
         this.scene.start('TransitionScene', {
             inventory: this.inventory,
             destination: 'hunting',
-            fuelCost: 20,
+            fuelCost: 0,
             nextScene: 'HuntingScene'
         });
     }
 
     goToAntarctic() {
-        if (this.inventory.fuel < 30) {
-            this.showMessage('Not enough fuel to reach Antarctic islands! You need at least 30 units.');
-            return;
-        }
-        // Go to transition scene, then to map (antarctic scene not yet implemented)
+        // Sailing is free - fuel is only for cooking
         this.scene.start('TransitionScene', {
             inventory: this.inventory,
             destination: 'antarctic',
-            fuelCost: 30,
+            fuelCost: 0,
             nextScene: 'MapScene' // Will change to 'AntarcticScene' when implemented
         });
     }
 
     goToPort() {
-        if (this.inventory.fuel < 10) {
-            this.showMessage('Not enough fuel to return to port! You need at least 10 units. Consider... alternatives.');
-            return;
-        }
-        // Go to transition scene, then to map (port scene not yet implemented)
+        // Sailing is free
         this.scene.start('TransitionScene', {
             inventory: this.inventory,
             destination: 'port',
-            fuelCost: 10,
+            fuelCost: 0,
             nextScene: 'MapScene' // Will change to 'PortScene' when implemented
         });
     }