fix: resolve queue management and metadata fetch bugs

- Reset isRemoving state in DeleteConfirmationModal on open and close to prevent UI freeze
- Filter sidebar queue count to exclude completed downloads
- Return fully resolved URL from backend metadata fetch to avoid 403s on one-time tokens

src/components/AddDownloadsModal.tsx

@@ -264,7 +264,7 @@ export const AddDownloadsModal = () => {
               password: keychainPassword
             });
             updatedItems[i] = {
-              url,
+              url: meta.url || url,
               file: lines.length === 1 && pendingAddFilename ? pendingAddFilename : meta.filename,
               size: meta.size,
               sizeBytes: meta.size_bytes,