Refactor(Structure): Move ADTs into adt/ folder, rename spel.rkt to main.rkt

New structure groups all ADT modules under adt/ directory, removing
redundant adt- prefix from filenames. Library names now read as
(pacman-project adt position) etc. All imports updated accordingly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pacman-project/adt/game.rkt

@@ -0,0 +1,48 @@
+#lang r7rs
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;                                Game ADT                                   ;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; Top-level game object that connects the level (logic) with the draw ADT
+;; (graphics). Registers callbacks for the game loop, keys, and drawing.
+
+(define-library (pacman-project adt game)
+  (import (scheme base)
+          (pacman-project constants)
+          (pacman-project adt level)
+          (pacman-project adt draw))
+  (export make-game)
+
+  (begin
+
+    ;; make-game :: -> game
+    (define (make-game)
+      (let ((level (make-level))
+            (draw (make-draw window-width-px window-height-px)))
+
+        ;; key-handler :: symbol, any -> /
+        ;; Processes key presses and forwards them to the level.
+        (define (key-handler status key)
+          (when (eq? status 'pressed)
+            ((level 'key-press!) key)))
+
+        ;; game-loop :: number -> /
+        ;; Called each frame for game state updates.
+        (define (game-loop delta-time)
+          ((level 'update!) delta-time))
+
+        ;; start! :: -> /
+        ;; Starts the game by registering all callbacks.
+        (define (start!)
+          ((draw 'set-game-loop!) game-loop)
+          ((draw 'set-key-callback!) key-handler)
+          ((draw 'start-drawing!) dispatch-game))
+
+        ;; dispatch-game :: symbol -> any
+        (define (dispatch-game msg)
+          (cond ((eq? msg 'start!) start!)
+                ((eq? msg 'level) level)
+                (else (error "Game ADT -- Unknown message:" msg))))
+
+        dispatch-game))))