Microsoft Teams Integration bot doesn't respond or prompt Sentry authentication

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

1. I open the[ "Sentry" app](https://teams.microsoft.com/l/app/5adee720-30de-4006-a342-d454317db1d4?source=agent-details-page) in MS Teams "Apps"
2. I click "Open" , and select our MS Teams channel ("Standard" type) and click "Go"
3. I'm taken to the channel I selected, with the "@Sentry" text in my chat dialog
4. I send the message to the channel

Additionally, Direct Messaging the app to prompt it for "help" or "link" does not respond

### Expected Result

I would expect the Sentry Teams App/Bot acknowledge or respond in either the channel it has been added to, or via Direct Message, and prompt us to link to our Sentry instance.

### Actual Result

### Product Area

Other

### Link

_No response_

### DSN

_No response_

### Version

_No response_

Start with the Sentry Microsoft Teams app/bot integration and trace the channel and direct-message authentication flow. Reproduce the reported channel and DM steps, then verify that the bot responds and provides the Sentry authentication or linking prompt in both contexts.

Written by the indexing model from the issue text.