Add calendar tool calling support in iOSCalendarAssistantWithLocalInf

[cmodi-meta]

This works in the remote iOSCalendarAssistant project but does not work in the local-inference project. There may be some fixes needed in the localAgent and local tool calling process to address this.

[jeffxtang]

I did some debugging and found two separate issues. #1 is

         messages.append(Message(type: .actionItems))
         try await actionItems(prompt: text)

         try await callTools(prompt: text)

never run after summarizeConversation, which could be related to the calls inside runnerQueue.async. Issue #2 is after commenting out

          messages.append(Message(type: .summary))
          try await summarizeConversation(prompt: text)

         messages.append(Message(type: .actionItems))
         try await actionItems(prompt: text)

the callTools runs but the step.delta is, unlike the remote demo, always .text and not .tool_call, which could be the model related (different prompt may trigger the too_call).