Complete Box2D to Planck.js migration

- Replace Box2D.js with Planck.js physics engine
- Update all require paths from 'Lib/Vendor/Box2D' to 'Lib/Vendor/Planck'
- Convert Box2D contact listeners to Planck.js event system
- Fix all method name capitalization (Get* -> get*, Set* -> set*)
- Update collision detection system for Planck.js compatibility
- Server now starts successfully and basic physics working
- Character can land on platforms - core physics functional

Major milestone: Game now running on modern, maintained physics engine

app/Game/Core/Physics/Engine.js

@@ -24,7 +24,7 @@ function (Settings, planck, CollisionDetector, nc) {
     Engine.prototype.setCollisionDetector = function () {
         
         var detector = new CollisionDetector(); 
-        this.world.on('begin-contact', detector.getListener());
+        detector.setupWorldEvents(this.world);
     }
 
     Engine.prototype.getWorldForRubeLoader = function() {