fix: resolve queue rendering and sorting desyncs

- Ensure `initDB` sorts active items by `queuePosition` before dispatching to preserve expected backend execution order on startup.
- Update `resumeDownload` to explicitly move items to the end of the queue visually by assigning a new max `queuePosition`, synchronizing frontend representation with backend queue behavior.
- Change `queuePosition` calculations to use `Math.max` via `reduce` rather than array `.length`, preventing duplicate queue position assignments upon deletions and avoiding call stack limit exceptions for massive queues.
- Modify `DownloadTable.tsx` sorting to enforce active downloads appearing at the top of the queue view, deferring to `queuePosition` only for pending items.
- Exclude active items from `moveInQueue` logic and UI to prevent visual corruption and silent queue scrambling.

src/components/DownloadItem.tsx

@@ -5,6 +5,7 @@ import { useDownloadProgressStore } from '../store/downloadStore';
 import { Play, Pause, MoreVertical, Clock, ArrowUp, ArrowDown } from 'lucide-react';
 import type { DownloadItem as DownloadItemType } from '../bindings/DownloadItem';
 import { canPauseDownload, canStartDownload, startActionLabel } from '../utils/downloadActions';
+import { isActiveDownloadStatus } from '../utils/downloads';
 
 interface DownloadItemProps {
   downloadId: string;
@@ -37,7 +38,8 @@ export const DownloadItem = React.memo<DownloadItemProps>(({
     return state.downloads
       .filter(candidate =>
         candidate.queueId === queueId &&
-        candidate.status !== 'completed'
+        candidate.status !== 'completed' &&
+        !(isActiveDownloadStatus(candidate.status) && candidate.status !== 'queued')
       )
       .sort((left, right) => (left.queuePosition ?? 0) - (right.queuePosition ?? 0))
       .map(candidate => candidate.id);