fix(library): optimize image scanning, fast raw preview extraction and lazy thumbnail loading

docker/frontend/src/main.tsx

@@ -37,18 +37,13 @@ function pick(route: string) {
   );
 }
 
-// Links are plain `<a href>`, so following one throws the page away — fine
-// everywhere except while a roll is being read: that scan runs for minutes in
-// this page's memory, and only the studio needs to be reachable from the
-// catalogue. So the click is taken over *only* while a scan is in flight, and
-// the browser keeps doing the navigating the rest of the time.
+// Intercept internal link clicks for instant SPA transitions without full page reload
 function Shell() {
   const [route, setRoute] = useState(() => window.location.pathname + window.location.search);
 
   useEffect(() => {
     const onClick = (e: MouseEvent) => {
       if (e.defaultPrevented || e.button !== 0 || e.metaKey || e.ctrlKey || e.shiftKey || e.altKey) return;
-      if (!scanSession()) return;
       const target = e.target as Element | null;
       const link = target?.closest?.('a');
       if (!(link instanceof HTMLAnchorElement)) return;