add cellular automata generator

addons/ca_level_generator/CaGeneratorSettings.cs

@@ -0,0 +1,23 @@
+using Godot;
+
+namespace Mr.BrickAdventures.Tools.CaLevelGenerator;
+
+public enum CaMode { Cave, Platform, Terrain }
+
+public class CaGeneratorSettings
+{
+    public CaMode Mode { get; set; } = CaMode.Cave;
+    public int Width { get; set; } = 40;
+    public int Height { get; set; } = 22;
+    public Vector2I Offset { get; set; } = Vector2I.Zero;
+    public float FillDensity { get; set; } = 0.48f;
+    public int SmoothingPasses { get; set; } = 4;
+    public bool BorderWalls { get; set; } = true;
+    public int Seed { get; set; } = 12345;
+    // TerrainSet == -1 → raw tile mode
+    public int TerrainSet { get; set; } = 0;
+    public int Terrain { get; set; } = 0;
+    // Used only when TerrainSet == -1
+    public int SourceId { get; set; } = 0;
+    public Vector2I AtlasCoords { get; set; } = Vector2I.Zero;
+}