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/Client/View/Pixi/DebugDraw.js

@@ -1,5 +1,5 @@
 define([
-    "Lib/Vendor/Box2D"
+    "Lib/Vendor/Planck"
 ],
  
 function (Box2D) {