feat(api): add account workspaces and signed content events

server/tests/WebDrop.Core.Tests/TestEnv.cs

@@ -68,6 +68,8 @@ public sealed class TestEnv : IDisposable
         var write = Random(32);
         var owner = Random(32);
 
+        settings ??= new ChannelSettings();
+        settings.Name ??= "Test space";
         Service.CreateChannel(new CreateChannelRequest
         {
             Id = id.ToBase64Url(),