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part of https://github.com/coder/coder/issues/21335
This moves updating app status (used by Tasks) into the workspace agent
API over dRPC. This will allow us to update the status without having to
re-authenticate each time, like we would with an HTTP PATCH request.
Further PRs in this stack will pipe these requests thru from the CLI MCP
server to the agentsock and finally to this dRPC call to coderd.