feat(server): agent socket endpoint, clear online status on boot

server/lib/server_web/channels/agent_socket.ex

@@ -0,0 +1,12 @@
+defmodule ServerWeb.AgentSocket do
+  @moduledoc "Entry socket for agents. Actual authentication happens in HostChannel.join/3."
+  use Phoenix.Socket
+
+  channel "host:*", ServerWeb.HostChannel
+
+  @impl true
+  def connect(_params, socket, _connect_info), do: {:ok, socket}
+
+  @impl true
+  def id(_socket), do: nil
+end

server/lib/server_web/endpoint.ex

@@ -15,6 +15,10 @@ defmodule ServerWeb.Endpoint do
     websocket: [connect_info: [session: @session_options]],
     longpoll: [connect_info: [session: @session_options]]
 
+  socket "/socket", ServerWeb.AgentSocket,
+    websocket: [timeout: 45_000],
+    longpoll: false
+
   # Serve at "/" the static files from "priv/static" directory.
   #
   # You should set gzip to true if you are running phx.digest