Fixed message loading

Root messages weren't being loaded since the refactor, and there was
dead code

pkg/tui/views/chat/cmds.go

@@ -21,7 +21,13 @@ func (m *Model) loadConversationMessages() tea.Cmd {
 		if err != nil {
 			return shared.MsgError(err)
 		}
-		return msgMessagesLoaded(messages)
+		rootMessages, err := m.App.LoadConversationRootMessages()
+		if err != nil {
+			return shared.MsgError(err)
+		}
+		return msgConversationMessagesLoaded{
+			messages, rootMessages,
+		}
 	}
 }