fix: address review feedback for health check endpoints

- Install wget in Web Dockerfile for compose healthcheck
- Ensure HttpListener response is always closed in BotHealthCheckHostedService
- Use ephemeral port in Bot health check test to avoid port conflicts
- Rename NpgsqlHealthCheck test to reflect actual behavior

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/GmRelay.Bot/Infrastructure/Health/BotHealthCheckHostedService.cs

@@ -72,10 +72,10 @@ public sealed class BotHealthCheckHostedService : IHostedService
 
     private async Task HandleRequestAsync(HttpListenerContext context)
     {
+        var response = context.Response;
         try
         {
             var request = context.Request;
-            var response = context.Response;
 
             if (request.Url?.AbsolutePath == "/health")
             {
@@ -88,12 +88,14 @@ public sealed class BotHealthCheckHostedService : IHostedService
             {
                 response.StatusCode = (int)HttpStatusCode.NotFound;
             }
-
-            response.Close();
         }
         catch (Exception ex)
         {
             _logger.LogError(ex, "Error handling health check request");
         }
+        finally
+        {
+            response.Close();
+        }
     }
 }