The existingworkspacesdk API allows connecting to a single workspace Agent. We need to add a new API call that creates a tailnet connected to every started agent in workspaces owned by the user.

To do this, we

1. Use the new HTTP endpoint and WorkspaceUpdates RPC to track all the workspaces and agents (Add new WorkspaceUpdates tailnet RPC #14716)
2. Program the agents into the tailnet using the enhanced support for multiple peers (enhance tailnetAPIConnector to support multiple peers #14729)
3. Program DNS records for the peers (Enhance tailnet to (optionally) configure DNS records for peers. #14718)

DNS naming scheme:

• <agent>.<workspace>.<user>.coder
  • <agent>.<workspace>.me.coder - works withme as an alias for the logged in user
• <workspace>.coder - alias that assumesme and that the workspace has only one agent.