Update service ports to 12015 for backend and 12016 for frontend; adjust configurations and documentation accordingly

frontend/app/static/app.js

@@ -79,6 +79,6 @@ document.addEventListener("DOMContentLoaded", () => {
       } catch (e) {
         console.error("Video polling error:", e);
       }
-    }, 12001);
+    }, 12016);
   }
 });