Refactor excalidraw-room service in docker-compose.yml to use a build context and update port mapping to 3002

docker-compose.yml

@@ -15,6 +15,10 @@ services:
       disable: true
 
   excalidraw-room:
-    image: excalidraw/excalidraw-room:latest
+    build:
+      context: ./excalidraw-room
+    environment:
+      # Collaboration WebSocket
+      PORT: 3002
     ports:
-      - '8802:80'
+      - '8802:3002'

excalidraw-room

@@ -0,0 +1 @@
+Subproject commit 03ff435860b508d7cd9e005cfc90f7977ae2a593