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>

tests/GmRelay.Bot.Tests/Infrastructure/Health/BotHealthCheckHostedServiceTests.cs

@@ -1,4 +1,5 @@
 using System.Net;
+using System.Net.Sockets;
 using GmRelay.Bot.Infrastructure.Health;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging.Abstractions;
@@ -8,13 +9,15 @@ namespace GmRelay.Bot.Tests.Infrastructure.Health;
 public sealed class BotHealthCheckHostedServiceTests : IDisposable
 {
     private readonly BotHealthCheckHostedService _service;
+    private readonly int _port;
 
     public BotHealthCheckHostedServiceTests()
     {
+        _port = GetAvailablePort();
         var config = new ConfigurationBuilder()
             .AddInMemoryCollection(new Dictionary<string, string?>
             {
-                ["HealthCheck:Prefix"] = "http://localhost:8081/"
+                ["HealthCheck:Prefix"] = $"http://localhost:{_port}/"
             })
             .Build();
 
@@ -35,8 +38,17 @@ public sealed class BotHealthCheckHostedServiceTests : IDisposable
 
         using var client = new HttpClient();
         client.Timeout = TimeSpan.FromSeconds(5);
-        var response = await client.GetAsync("http://localhost:8081/health");
+        var response = await client.GetAsync($"http://localhost:{_port}/health");
 
         Assert.Equal(HttpStatusCode.OK, response.StatusCode);
     }
+
+    private static int GetAvailablePort()
+    {
+        var listener = new TcpListener(IPAddress.Loopback, 0);
+        listener.Start();
+        var port = ((IPEndPoint)listener.LocalEndpoint).Port;
+        listener.Stop();
+        return port;
+    }
 }

tests/GmRelay.Bot.Tests/Web/WebHealthEndpointTests.cs

@@ -73,7 +73,7 @@ public sealed class WebHealthEndpointTests
     }
 
     [Fact]
-    public async Task NpgsqlHealthCheck_ShouldReturnHealthy_WhenDatabaseIsAccessible()
+    public async Task NpgsqlHealthCheck_ShouldReturnUnhealthy_WhenDatabaseIsInaccessible()
     {
         var dataSource = NpgsqlDataSource.Create("Host=localhost;Port=5432;Database=gmrelay_db;Username=gmrelay;Password=fake");
         var healthCheck = new NpgsqlHealthCheck(dataSource);