test(data): parent delete with children is restricted

tests/ClaudeDo.Worker.Tests/Repositories/TaskRepositoryPlanningTests.cs

@@ -283,6 +283,25 @@ public sealed class TaskRepositoryPlanningTests : IDisposable
         Assert.False(ok);
     }
 
+    [Fact]
+    public async Task DeleteAsync_ParentWithChildren_ThrowsOrDoesNotDelete()
+    {
+        var listId = await CreateListAsync();
+        var parent = MakeTask(listId, TaskStatus.Planning);
+        await _tasks.AddAsync(parent);
+        await _tasks.CreateChildAsync(parent.Id, "c", null, null, null);
+
+        // ExecuteDelete bypasses EF change tracking, so SQLite's FK enforcement
+        // (foreign_keys = ON, set by ClaudeDoDbContext) throws SqliteException directly.
+        await Assert.ThrowsAsync<Microsoft.Data.Sqlite.SqliteException>(async () =>
+        {
+            await _tasks.DeleteAsync(parent.Id);
+        });
+
+        var stillThere = await _tasks.GetByIdAsync(parent.Id);
+        Assert.NotNull(stillThere);
+    }
+
     [Fact]
     public async Task GetNextQueuedAgentTask_SkipsDraftPlanningPlanned()
     {