Add project files.

Program.cs

@@ -0,0 +1,69 @@
+using SFML.Graphics;
+using SFML.Window;
+using SFML.System;
+using System.Diagnostics;
+using FluidSim.Core;
+
+namespace FluidSim;
+
+public class Program
+{
+    private const int SampleRate = 44100;
+    private static volatile bool running = true;
+
+    public static void Main()
+    {
+        var mode = new VideoMode(new Vector2u(1280, 720));
+        var window = new RenderWindow(mode, "Fluid Simulation");
+        window.SetVerticalSyncEnabled(true);
+        window.Closed += (_, _) => { running = false; window.Close(); };
+
+        var soundEngine = new SoundEngine(bufferCapacity: 2048);
+        soundEngine.Volume = 70;
+        soundEngine.Start();
+
+        double lastAudioTime = 0.0;
+        var stopwatch = Stopwatch.StartNew();
+
+        int warmupSamples = SampleRate / 2;
+        float[] warmup = new float[warmupSamples];
+        for (int i = 0; i < warmupSamples; i++)
+            warmup[i] = 0;
+
+        soundEngine.WriteSamples(warmup, warmupSamples);
+        lastAudioTime = stopwatch.Elapsed.TotalSeconds;
+
+        const int chunkSize = 2048;
+        float[] buffer = new float[chunkSize];
+
+        Simulation.Initialize(SampleRate);
+
+        while (window.IsOpen)
+        {
+            window.DispatchEvents();
+
+            double currentTime = stopwatch.Elapsed.TotalSeconds;
+            double elapsed = currentTime - lastAudioTime;
+            int samplesNeeded = (int)(elapsed * SampleRate);
+
+            while (samplesNeeded > 0 && running)
+            {
+                int toGenerate = Math.Min(samplesNeeded, chunkSize);
+                for (int i = 0; i < toGenerate; i++)
+                {
+                    buffer[i] = Simulation.Process();
+                }
+                soundEngine.WriteSamples(buffer, toGenerate);
+                samplesNeeded -= toGenerate;
+            }
+
+            lastAudioTime = currentTime;
+
+            window.Clear(Color.Black);
+            window.Display();
+        }
+
+        soundEngine.Dispose();
+        window.Dispose();
+    }
+}