refactor: remove unused useMemo and related code in LoadingScreen component

src/App.tsx

@@ -3,7 +3,6 @@ import React, {
   useEffect,
   useCallback,
   useRef,
-  useMemo,
 } from "react";
 import { openDB, type IDBPDatabase } from "idb";
 import {

src/components/LoadingScreen.tsx

@@ -43,7 +43,6 @@ export const LoadingScreen = ({
   const canvasRef = useRef<HTMLCanvasElement>(null);
   const dropdownBtnRef = useRef<HTMLButtonElement>(null);
   const dropdownRef = useRef<HTMLDivElement>(null);
-  const wrapperRef = useRef<HTMLDivElement>(null); // NEW: anchor for centering
 
   // For keyboard navigation
   const [activeIndex, setActiveIndex] = useState(
@@ -189,53 +188,6 @@ export const LoadingScreen = ({
     handleModelSelect,
   ]);
 
-  // Recompute portal position on open + resize
-  const [, forceRerender] = useState(0);
-  useEffect(() => {
-    const onResize = () => forceRerender((x) => x + 1);
-    window.addEventListener("resize", onResize);
-    return () => window.removeEventListener("resize", onResize);
-  }, []);
-
-  // Compute portal style based on the whole button group (center + clamp + optional drop-up)
-  const portalStyle = useMemo(() => {
-    if (typeof window === "undefined") return {};
-    const anchor = wrapperRef.current || dropdownBtnRef.current;
-    if (!anchor) return {};
-
-    const rect = anchor.getBoundingClientRect();
-
-    const margin = 8;
-    const minWidth = 320;
-    const dropdownWidth = Math.max(rect.width, minWidth);
-
-    // Center
-    let left = Math.round(rect.left + rect.width / 2 - dropdownWidth / 2);
-    // Clamp to viewport
-    left = Math.min(
-      Math.max(margin, left),
-      window.innerWidth - dropdownWidth - margin
-    );
-
-    // Flip up if not enough space below
-    const spaceBelow = window.innerHeight - rect.bottom;
-    const spaceAbove = rect.top;
-    const estimatedItemH = 56; // rough item height
-    const estimatedPad = 16;
-    const estimatedHeight =
-      estimatedItemH * Math.min(MODEL_OPTIONS.length, 6) + estimatedPad;
-    const dropUp = spaceBelow < estimatedHeight && spaceAbove > spaceBelow;
-
-    const top = dropUp ? rect.top - estimatedHeight - 8 : rect.bottom + 8;
-
-    return {
-      position: "fixed" as const,
-      left: `${left}px`,
-      top: `${top}px`,
-      width: `${dropdownWidth}px`,
-      zIndex: 100,
-    };
-  }, []);
 
   return (
     <div className="relative flex flex-col items-center justify-center min-h-screen bg-gradient-to-br from-gray-900 via-slate-900 to-gray-900 text-white p-6 overflow-hidden">