Clamp AI summarize lengths for CV rewrite

JobTrackerApi.Tests/SummarizerServiceTests.cs

@@ -0,0 +1,49 @@
+using System.Net;
+using System.Net.Http;
+using System.Text;
+using Microsoft.Extensions.Caching.Memory;
+using Moq;
+using Xunit;
+using JobTrackerApi.Services;
+
+namespace JobTrackerApi.Tests;
+
+public sealed class SummarizerServiceTests
+{
+    [Fact]
+    public async Task Summarize_section_clamps_lengths_to_ai_service_limits()
+    {
+        var handler = new CapturingHandler();
+        var httpClient = new HttpClient(handler)
+        {
+            BaseAddress = new Uri("http://localhost:8001")
+        };
+
+        var httpFactory = new Mock<IHttpClientFactory>();
+        httpFactory.Setup(x => x.CreateClient("ai-service")).Returns(httpClient);
+
+        using var memoryCache = new MemoryCache(new MemoryCacheOptions());
+        var service = new SummarizerService(httpFactory.Object, memoryCache);
+
+        var result = await service.SummarizeSectionAsync("Rewrite this CV", "Professional Summary\nBuilt backend systems.", 1800, 400);
+
+        Assert.Equal("ok", result);
+        Assert.NotNull(handler.LastBody);
+        Assert.Contains("\"max_length\":256", handler.LastBody);
+        Assert.Contains("\"min_length\":180", handler.LastBody);
+    }
+
+    private sealed class CapturingHandler : HttpMessageHandler
+    {
+        public string? LastBody { get; private set; }
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            LastBody = request.Content is null ? null : await request.Content.ReadAsStringAsync(cancellationToken);
+            return new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent("{\"summary\":\"ok\"}", Encoding.UTF8, "application/json")
+            };
+        }
+    }
+}