fix(cv): make profile saves atomic

JobTrackerApi.Tests/CareerProfileServiceTests.cs

@@ -34,6 +34,43 @@ public sealed class CareerProfileServiceTests
         Assert.False(string.IsNullOrWhiteSpace(saved.Jobs[0].Id));
     }
 
+    [Fact]
+    public async Task SaveVersionAsync_replaces_duplicate_item_ids_without_dropping_entries()
+    {
+        await using var db = NewContext("user-1");
+        var service = new CareerProfileService(db);
+        var profile = new StructuredCvProfile
+        {
+            Jobs = { new StructuredCvJob { Id = "shared", Title = "Engineer", Company = "Acme" } },
+            Education = { new StructuredCvEducation { Id = "shared", Qualification = "BSc", Institution = "University" } },
+        };
+
+        var saved = await service.SaveVersionAsync("user-1", profile, "manual", default);
+
+        Assert.Equal("shared", saved.Jobs[0].Id);
+        Assert.NotEqual(saved.Jobs[0].Id, saved.Education[0].Id);
+        Assert.Single(await db.CareerExperiences.IgnoreQueryFilters().ToListAsync());
+        Assert.Single(await db.CareerEducations.IgnoreQueryFilters().ToListAsync());
+    }
+
+    [Fact]
+    public async Task LoadStructuredAsync_hides_race_affected_duplicate_child_rows()
+    {
+        await using var db = NewContext("user-1");
+        var profile = new CareerProfile { OwnerUserId = "user-1", ProfileJson = "{}", LongTailJson = "{}", Version = 1 };
+        db.CareerProfiles.Add(profile);
+        await db.SaveChangesAsync();
+        db.CareerExperiences.AddRange(
+            new CareerExperience { CareerProfileId = profile.Id, OwnerUserId = "user-1", ItemKey = "duplicate", SortOrder = 0, Title = "Engineer" },
+            new CareerExperience { CareerProfileId = profile.Id, OwnerUserId = "user-1", ItemKey = "duplicate", SortOrder = 0, Title = "Engineer" });
+        await db.SaveChangesAsync();
+
+        var loaded = await new CareerProfileService(db).LoadStructuredAsync("user-1", default);
+
+        Assert.Single(loaded.Jobs);
+        Assert.Equal("duplicate", loaded.Jobs[0].Id);
+    }
+
     [Fact]
     public async Task SaveVersionAsync_preserves_existing_ids_across_saves()
     {

JobTrackerApi.Tests/CvBuilderTests.cs

@@ -537,4 +537,15 @@ public sealed class CvBuilderTests
         Assert.Contains("class=\"paragraphs\"><p>I confirm these details.</p>", html);
     }
 
+    [Fact]
+    public void Settings_normalization_removes_duplicate_entry_order_keys()
+    {
+        var settings = CvVariantSettingsJson.Normalize(new CvVariantSettings
+        {
+            Sections = { new CvSectionSetting { Key = "experience", ItemOrder = new() { "first", "first", "second", " " } } },
+        });
+
+        Assert.Equal(new[] { "first", "second" }, settings.Sections[0].ItemOrder);
+    }
+
 }