Complete phase 39 school owners with owner-scoped API, menu, and tests.

Drop golden save load tests in favor of incompatible-save behavior; dress legacy people files on reload; fix AppHost isolation for multi-user socket and save cleanup.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/HSchool.AppHost.Tests/SchoolOwnerApiTests.cs

@@ -1,4 +1,6 @@
 using System.Net.Http.Json;
+using System.Text.Json;
+using System.Text.Json.Nodes;
 
 namespace HSchool.AppHost.Tests;
 
@@ -37,6 +39,14 @@ public class SchoolOwnerApiTests(AppHostFixture fixture)
         Assert.Equal(2, aliceList.Others.Count);
         Assert.All(aliceList.Others, other => Assert.Equal("OwnerBob", other.Owner));
         Assert.DoesNotContain(aliceList.Schools, school => school.Name.StartsWith("Bob", StringComparison.Ordinal));
+
+        foreach (var client in new[] { alice, bob })
+        {
+            client.Dispose();
+        }
+
+        using var cleanup = fixture.App.CreateHttpClient("server");
+        await SchoolApiTests.WipeAllSavesAsync(cleanup);
     }
 
     [Fact]
@@ -99,6 +109,12 @@ public class SchoolOwnerApiTests(AppHostFixture fixture)
             TestContext.Current.CancellationToken);
         Assert.Equal(HttpStatusCode.Forbidden, hire.StatusCode);
         Assert.Equal("not-owner", await SchoolApiTests.ProblemCodeAsync(hire));
+
+        owner.Dispose();
+        guest.Dispose();
+
+        using var cleanup = fixture.App.CreateHttpClient("server");
+        await SchoolApiTests.WipeAllSavesAsync(cleanup);
     }
 
     [Fact]
@@ -108,19 +124,41 @@ public class SchoolOwnerApiTests(AppHostFixture fixture)
         await SchoolApiTests.WipeAllSavesAsync(wipe);
 
         var first = await CreateUserAsync("SaveAlpha");
+        var created = await SchoolApiTests.CreateAsync(first, "Бесхозная", Start);
+
         var directory = await SavesDirectoryAsync(first);
-        var golden = Path.Combine(AppContext.BaseDirectory, "golden", "current");
-        foreach (var file in Directory.EnumerateFiles(golden))
+        var saveFiles = new[]
         {
-            File.Copy(file, Path.Combine(directory, Path.GetFileName(file)), overwrite: true);
+            $"{created.Id}.json",
+            $"{created.Id}.people.json",
+            $"{created.Id}.timetable.json",
+        };
+        var copies = saveFiles
+            .Select(name => Path.Combine(directory, name))
+            .Where(File.Exists)
+            .ToDictionary(path => path, File.ReadAllBytes);
+
+        await SchoolApiTests.WipeAllSavesAsync(first);
+
+        foreach (var (copiedPath, bytes) in copies)
+        {
+            File.WriteAllBytes(copiedPath, bytes);
         }
 
+        var schoolSavePath = Path.Combine(directory, $"{created.Id}.json");
+        var node = JsonNode.Parse(File.ReadAllText(schoolSavePath))
+            ?? throw new InvalidOperationException("School save parsed to nothing.");
+        node.AsObject().Remove("owner");
+        File.WriteAllText(
+            schoolSavePath,
+            node.ToJsonString(new JsonSerializerOptions { WriteIndented = true }));
+
         using var reload = await first.PostAsync("/api/dev/reload-schools", content: null, TestContext.Current.CancellationToken);
         reload.EnsureSuccessStatusCode();
 
         var firstList = await SchoolApiTests.GetSchoolsAsync(first);
         Assert.Empty(firstList.Schools);
-        var orphan = Assert.Single(firstList.Others, other => other.Name == "Золотая");
+        var orphan = Assert.Single(firstList.Others, other => other.Name == "Бесхозная");
         Assert.Null(orphan.Owner);
 
         var second = await CreateUserAsync("SaveBeta");
@@ -129,6 +167,12 @@ public class SchoolOwnerApiTests(AppHostFixture fixture)
 
         var after = await SchoolApiTests.GetSchoolsAsync(second);
         Assert.DoesNotContain(after.Others, other => other.Id == orphan.Id);
+
+        first.Dispose();
+        second.Dispose();
+
+        using var cleanup = fixture.App.CreateHttpClient("server");
+        await SchoolApiTests.WipeAllSavesAsync(cleanup);
     }
 
     private async Task<HttpClient> CreateUserAsync(string userName) =>