[516] Scaling and TGUI fixes (#28809)

* [516] Scaling and TGUI fixes

* fuck it we go with this

* ???

* final changes

* whoops

code/modules/client/client_defines.dm

@@ -232,3 +232,6 @@
 
 	/// Cache of MD5'd UIDs. This is to stop clients from poking at object UIDs and being exploity with them
 	var/list/m5_uid_cache = list()
+
+	/// If this client has any windows scaling applied
+	var/window_scaling

code/modules/client/client_procs.dm

@@ -414,6 +414,8 @@
 			to_chat(src, message)
 		GLOB.clientmessages.Remove(ckey)
 
+	acquire_dpi()
+
 	if(SSinput.initialized)
 		set_macros()
 
@@ -1327,6 +1329,15 @@
 	to_chat(src, "All sounds stopped.")
 	tgui_panel?.stop_music()
 
+/client/proc/acquire_dpi()
+	set waitfor = FALSE
+
+	// Remove with 516
+	if(byond_version < 516)
+		return
+
+	window_scaling = text2num(winget(src, null, "dpi"))
+
 #undef LIMITER_SIZE
 #undef CURRENT_SECOND
 #undef SECOND_COUNT