feat: improve media library layout and loading behavior

- Added a hidden anchor element to the media library for smooth scrolling to the top of the grid after uploads.
- Introduced a sequence reference to manage concurrent media item fetch requests, ensuring accurate loading states.
- Updated upload summary messaging to include a note about the list being refreshed after uploads.
- Enhanced loading state management to prevent unnecessary updates when fetch requests are out of sync.

frontend/src/app.css

@@ -5563,6 +5563,14 @@ a.analysis-split__nav-item {
   color: var(--text2);
   flex: 1 1 200px;
 }
+.media-library__grid-top-anchor {
+  height: 1px;
+  margin: 0;
+  padding: 0;
+  overflow: hidden;
+  visibility: hidden;
+  pointer-events: none;
+}
 .media-library__upload-icon {
   vertical-align: middle;
   margin-right: 6px;

frontend/src/pages/MediaLibraryPage.jsx

@@ -262,6 +262,8 @@ export default function MediaLibraryPage() {
   const [uploadClubId, setUploadClubId] = useState('')
   const [uploadBusy, setUploadBusy] = useState(false)
   const [uploadSummary, setUploadSummary] = useState('')
+  const mediaListFetchSeqRef = useRef(0)
+  const gridTopAnchorRef = useRef(null)
 
   const loadClubs = useCallback(async () => {
     try {
@@ -277,6 +279,7 @@ export default function MediaLibraryPage() {
   }, [loadClubs])
 
   const loadItems = useCallback(async () => {
+    const seq = ++mediaListFetchSeqRef.current
     setLoading(true)
     setError('')
     try {
@@ -294,6 +297,7 @@ export default function MediaLibraryPage() {
           ? { uploaded_by: Number(filterUploaderId) }
           : {}),
       })
+      if (seq !== mediaListFetchSeqRef.current) return
       setItems(res.items || [])
       setViewer(res.viewer || null)
       if (res.filter_meta?.uploaders?.length) {
@@ -301,9 +305,10 @@ export default function MediaLibraryPage() {
       }
       setSelected(new Set())
     } catch (e) {
+      if (seq !== mediaListFetchSeqRef.current) return
       setError(e.message || String(e))
     } finally {
-      setLoading(false)
+      if (seq === mediaListFetchSeqRef.current) setLoading(false)
     }
   }, [lifecycle, q, mediaKind, filterClubId, filterUploaderId, isSuperadmin, viewer?.show_uploader_meta])
 
@@ -485,9 +490,15 @@ export default function MediaLibraryPage() {
         ...(uploadVis === 'club' ? { club_id: Number(uploadClubId) } : {}),
       })
       setUploadSummary(
-        `Archiv-Upload: neu ${res.created_count}, bereits vorhanden ${res.duplicate_count}, fehlgeschlagen ${res.failed_count}.`,
+        `Archiv-Upload: neu ${res.created_count}, bereits vorhanden ${res.duplicate_count}, fehlgeschlagen ${res.failed_count}. Liste aktualisiert.`,
       )
+      if (res.created_count > 0 || res.duplicate_count > 0) {
+        setFilterUploaderId('')
+      }
       await loadItems()
+      window.requestAnimationFrame(() => {
+        gridTopAnchorRef.current?.scrollIntoView({ behavior: 'smooth', block: 'start' })
+      })
     } catch (err) {
       window.alert(err.message || String(err))
     } finally {
@@ -682,6 +693,8 @@ export default function MediaLibraryPage() {
           </p>
         ) : null}
 
+        <div ref={gridTopAnchorRef} className="media-library__grid-top-anchor" aria-hidden="true" />
+
         {loading && !items.length ? <div className="spinner media-library__spinner" /> : null}
 
         {!loading && !items.length && !error ? (