add cloud agents (#530)

* fix rebase conflicts

* cleanup

* linter fixes

* protocol update

* add client settings endpoint to the api

* use errors.New for plain string

* add nanpa and update to latest protocol and server-sdk-go

Author: real-danm

.nanpa/agent-hosting.kdl

@@ -0,0 +1 @@
+minor type="added" "added support for agent hosting"