feat(bot): add Microsoft Teams integration

[RSO]

Summary

• Adds Microsoft Teams bot installation/linking support and Teams platform identity lookup.
• Updates bot session callbacks to reply through the stored platform adapter instead of assuming Slack.
• Adds regression coverage for Teams install/link helpers and Teams callback replies.

Verification

• Tested a Teams bot request locally and confirmed the callback posts the completed Cloud Agent result back to the Teams thread.

Visual Changes

N/A

Reviewer Notes

• Draft PR for manual review of the Teams callback continuation behavior and the Microsoft Graph conversation-context fallback logs.
• Automated checks run locally before push: format hook and typecheck hook completed successfully during git push.