feat(world-gen): add CaveCarver skeleton (no-op Carve)

World/WorldGen/CaveCarver.cs

@@ -0,0 +1,33 @@
+using OpenTK.Mathematics;
+using VoxelEngine.Core;
+using VoxelEngine.World.Blocks;
+using VoxelChunk = VoxelEngine.World.Chunk.Chunk;
+
+namespace VoxelEngine.World.WorldGen;
+
+// Carves caves into an already-terrain-filled chunk. Stateless after
+// construction; the carve methods are pure functions of (chunk, chunkPos).
+// Safe to share across worker threads.
+public sealed class CaveCarver
+{
+    private readonly int _seed;
+    private readonly BlockRegistry _blocks;
+    private readonly Configuration _cfg;
+    private readonly FastNoiseLite _caveNoise;
+
+    public CaveCarver(int seed, BlockRegistry blocks, Configuration cfg)
+    {
+        this._seed = seed;
+        this._blocks = blocks;
+        this._cfg = cfg;
+
+        this._caveNoise = new FastNoiseLite(seed + 100);
+        this._caveNoise.SetNoiseType(FastNoiseLite.NoiseType.OpenSimplex2);
+        this._caveNoise.SetFrequency(cfg.CaveNoiseFrequency);
+    }
+
+    public void Carve(VoxelChunk chunk, Vector3i chunkPos)
+    {
+        // Implemented in Tasks 5 and 6.
+    }
+}