add player rating to the db

main-server/app/channels/matchmaking_channel.rb

@@ -3,7 +3,7 @@
 # Client flow:
 #   1. Connect: ws(s)://host/cable?token=<JWT>
 #   2. Subscribe to "MatchmakingChannel"
-#   3. Send { action: "start", rating: <optional int> } to enter the queue
+#   3. Send { action: "start" } to enter the queue
 #   4. Receive { type: "matched", ... } or { type: "timeout" }
 #   5. Disconnecting (or sending { action: "stop" }) cancels the search.
 class MatchmakingChannel < ApplicationCable::Channel
@@ -17,8 +17,8 @@ class MatchmakingChannel < ApplicationCable::Channel
     end
   end
 
-  def start(data)
-    MatchmakingService.enqueue(current_user.id, rating: data["rating"])
+  def start(_data)
+    MatchmakingService.enqueue(current_user.id, rating: current_user.rating)
   end
 
   def stop