Added MidrandShop feature and spl;it extensions and healthchecks

LiteCharms.Features/HealthChecks/PostgresMidrandShopHealthCheck.cs

@@ -0,0 +1,28 @@
+using static LiteCharms.Features.Extensions.Postgres;
+
+namespace LiteCharms.Features.HealthChecks;
+
+public class PostgresMidrandShopHealthCheck(IConfiguration configuration) : IHealthCheck
+{
+    private readonly string connectionString = configuration.GetConnectionString(MidrandShopDbConfigName)!;
+
+    public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var dataSource = NpgsqlDataSource.Create(connectionString);
+            await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
+
+            await using var command = connection.CreateCommand();
+            command.CommandText = "SELECT 1";
+
+            await command.ExecuteScalarAsync(cancellationToken);
+
+            return HealthCheckResult.Healthy($"{MidrandShopDbConfigName} is responsive.");
+        }
+        catch (Exception ex)
+        {
+            return HealthCheckResult.Unhealthy($"{MidrandShopDbConfigName} is unreachable.", ex);
+        }
+    }
+}