feat: Implement enemy spawning and movement logic in the level manager

scripts/actors/enemy.gd

@@ -0,0 +1,53 @@
+## enemy.gd
+# Enemy character script. Each turn, chases the player one tile using pathfinding.
+class_name Enemy
+extends Character
+
+# Movement speed in pixels per second.
+const SPEED: float = 200.0
+# Distance threshold for snapping to a tile (prevents jitter).
+const ARRIVAL_THRESHOLD: float = 4.0
+
+# Reference to the player — set by LevelManager after spawning.
+var _player: Player
+# True while animating toward _move_target.
+var _is_moving: bool = false
+# World position of the tile this enemy is stepping toward.
+var _move_target: Vector2 = Vector2.ZERO
+
+
+# Called by TurnManager. Pathfinds to the player and steps one tile closer.
+func take_turn() -> void:
+	var my_tile := LevelManager.world_to_tile(position)
+	var player_tile := LevelManager.world_to_tile(_player.position)
+	var path := LevelManager.find_path(my_tile, player_tile)
+	# path[0] is own tile; path[-1] is the player's tile (don't step there).
+	if path.size() < 2:
+		turn_finished.emit()
+		return
+	# Stop one tile away from the player — don't overlap.
+	if path.size() == 2:
+		turn_finished.emit()
+		return
+	_move_target = LevelManager.tile_to_world(path[1])
+	_is_moving = true
+
+
+# Glides toward _move_target each frame. Emits turn_finished on arrival.
+func _physics_process(_delta: float) -> void:
+	if not _is_moving:
+		velocity = Vector2.ZERO
+		move_and_slide()
+		return
+
+	var to_target: Vector2 = _move_target - position
+
+	if to_target.length() < ARRIVAL_THRESHOLD:
+		position = _move_target
+		velocity = Vector2.ZERO
+		move_and_slide()
+		_is_moving = false
+		turn_finished.emit()
+	else:
+		velocity = to_target.normalized() * SPEED
+		move_and_slide()