invert y axis and fix tracker text

backend/psn_server.py

@@ -49,7 +49,7 @@ def get_elapsed_time_ms():
 
 
 def pic_to_scene_coords(x, y):
-    return x / 200, y / 200
+    return x / 200, - y / 200
 
 
 async def update_all_clients(app: web.Application):

frontend/src/components/Drag.svelte

@@ -54,5 +54,5 @@
   style={`transform: translate(${x}px, ${y}px)`}
   class="absolute flex h-40 w-40 touch-none items-center justify-center rounded-full border-red-400 bg-red-400"
 >
-  dragable
+  Tracker {id}
 </div>