Refactor unit classes to reduce code duplication and improve maintainability

- Updated the Unit base class to include common attributes and methods for all units.
- Refactored Bomb, Point, and Rat classes to inherit from the new Unit class structure.
- Implemented a consistent die method across units for better cleanup.
- Removed redundant code in unit initialization and added specific attributes where necessary.
- Deleted obsolete configuration file and added a comprehensive architecture guide for future reference.

units/bomb.py

@@ -8,16 +8,9 @@ AGE_THRESHOLD = 200
 
 class Bomb(Unit):
     def __init__(self, game, position=(0,0), id=None):
-        super().__init__(position)
-        self.id = id if id else uuid.uuid4()
-        self.game = game
-        self.position = position
-        self.bbox = (0, 0, 0, 0)
-        self.stop = 0
-        self.age = 0
-        self.speed = 4
-        self.partial_move = 0
-        self.position_before = position
+        super().__init__(game, position, id)
+        # Specific attributes for bombs
+        self.speed = 4  # Bombs age faster
         self.fight = False
 
     def move(self):
@@ -54,16 +47,21 @@ class Timer(Bomb):
             self.die()
             
     def die(self, unit=None, score=None):
+        """Handle bomb explosion and chain reactions."""
         score = 10
         print("BOOM")
-        if not unit:
-            unit = self
+        target_unit = unit if unit else self
         self.game.play_sound("BOMB.WAV")
+        
+        # Use base class cleanup with error handling
         try:
-            self.game.units.pop(unit.id)
+            if target_unit.id in self.game.units:
+                self.game.units.pop(target_unit.id)
         except:
-            print(f"Unit {unit.id} already dead")
-        self.game.spawn_unit(Explosion, unit.position)
+            print(f"Unit {target_unit.id} already dead")
+            
+        # Bomb-specific behavior: create explosion
+        self.game.spawn_unit(Explosion, target_unit.position)
         for direction in ["N", "S", "E", "W"]:
             x, y = unit.position
             while True: