NEON-15: dispose shared NpgsqlDataSource on host shutdown

server/NeonSprawl.Server.Tests/InMemoryWebApplicationFactory.cs

@@ -21,7 +21,8 @@ public sealed class InMemoryWebApplicationFactory : WebApplicationFactory<Progra
                 if (d.ServiceType == typeof(IPositionStateStore) ||
                     d.ServiceType == typeof(NpgsqlDataSource) ||
                     (d.ServiceType == typeof(IHostedService) &&
-                     d.ImplementationType == typeof(PostgresDevPlayerSeedHostedService)))
+                     (d.ImplementationType == typeof(PostgresDevPlayerSeedHostedService) ||
+                      d.ImplementationType == typeof(NpgsqlDataSourceShutdownHostedService))))
                 {
                     services.RemoveAt(i);
                 }

server/NeonSprawl.Server/Game/PositionState/NpgsqlDataSourceShutdownHostedService.cs

@@ -0,0 +1,15 @@
+using Microsoft.Extensions.Hosting;
+using Npgsql;
+
+namespace NeonSprawl.Server.Game.PositionState;
+
+/// <summary>Disposes the shared <see cref="NpgsqlDataSource"/> when the host stops. Registered before <see cref="PostgresDevPlayerSeedHostedService"/> so <see cref="IHostedService.StopAsync"/> runs last (NEON-15).</summary>
+internal sealed class NpgsqlDataSourceShutdownHostedService(NpgsqlDataSource dataSource) : IHostedService
+{
+    public Task StartAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+
+    public async Task StopAsync(CancellationToken cancellationToken)
+    {
+        await dataSource.DisposeAsync();
+    }
+}

server/NeonSprawl.Server/Game/PositionState/PositionStateServiceCollectionExtensions.cs

@@ -13,7 +13,8 @@ public static class PositionStateServiceCollectionExtensions
         if (!string.IsNullOrWhiteSpace(cs))
         {
             var trimmed = cs.Trim();
-            services.AddSingleton(_ => Npgsql.NpgsqlDataSource.Create(trimmed));
+            services.AddSingleton<Npgsql.NpgsqlDataSource>(_ => Npgsql.NpgsqlDataSource.Create(trimmed));
+            services.AddHostedService<NpgsqlDataSourceShutdownHostedService>();
             services.AddHostedService<PostgresDevPlayerSeedHostedService>();
             services.AddSingleton<IPositionStateStore, PostgresPositionStateStore>();
         }