Generate a ready-to-sideload Teams app package during azd deploy for activity-protocol agents

### Summary

For activity-protocol (Teams) hosted agents, `azd deploy` currently creates the Azure Bot + Teams channel and writes a `TEAMS_APP_SETUP.md` guide, but the user still has to assemble a Teams app package (manifest, icons, bot entry) by hand before they can sideload and try the agent in Teams.

### Proposal

After the bot is created, have the `azure.ai.agents` extension call the Foundry Microsoft 365 packaging API (`POST /agents/{name}/microsoft365/zip`) to download a ready-to-sideload Teams app package (`appPackage.zip`) next to the agent source, and update the setup guide to lead with sideloading that package (Teams UI upload or `atk install --scope Personal`, no Teams admin needed).

### Scope

- Activity-protocol agents only; non-activity deploys unaffected.
- Best-effort: packaging failures never fail the deploy; the guide falls back to manual packaging steps.
- Publishing to the org catalog (Shared/Tenant, admin-gated) is out of scope.

Tracking issue for the change in the linked PR.

Start at the azure.ai.agents extension path used by azd deploy and the generated TEAMS_APP_SETUP.md guide. Trace activity-protocol agent deployment through the POST /agents/{name}/microsoft365/zip packaging call; done means a best-effort appPackage.zip is available beside the source, the guide leads with sideloading it, and packaging failures preserve the manual fallback without failing deploy.

Written by the indexing model from the issue text.