fix bad persistent client handling (#18460)

code/modules/mob/new_player/lobby_browser.dm

@@ -146,7 +146,7 @@
 			handle_server_news()
 			return TRUE
 		if("give_feedback")
-			if(!SSsqlite.can_submit_feedback(GLOB.persistent_clients_by_ckey[ckey]))
+			if(!SSsqlite.can_submit_feedback(persistent_client.client))
 				return
 
 			if(client.feedback_form)

code/modules/mob/new_player/login.dm

@@ -18,6 +18,7 @@
 	GLOB.new_player_list += src
 
 	created_for = ckey
+	client.persistent_client.set_mob(src)
 
 	addtimer(CALLBACK(src, PROC_REF(do_after_login)), 4 SECONDS, TIMER_DELETE_ME)
 	initialize_lobby_screen()

code/modules/mob/new_player/logout.dm

@@ -17,6 +17,6 @@
 	return
 
 /mob/new_player/proc/disable_lobby_browser()
-	var/client/exiting_client = GLOB.persistent_clients_by_ckey[ckey]
+	var/client/exiting_client = persistent_client.client
 	if(exiting_client)
 		winset(exiting_client, "lobby_browser", "is-disabled=true;is-visible=false")