feat(upload): enhance audio upload handling and user feedback

- Introduced a new warning for users uploading non-FLAC or WAV formats, indicating that these formats should only be used as a last resort.
- Added functionality to highlight files needing format attention in the upload queue.
- Updated the UI to provide clearer guidance on acceptable audio formats during uploads.
- Improved documentation to reflect changes in upload requirements and user interface updates.

apps/web/src/pages/admin/UploadQueuePage.tsx

@@ -5,6 +5,7 @@ import { useEffect, useMemo, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 
 import { useSession } from '../../app/session';
+import { needsFormatAttention } from '../../features/uploads/files';
 import { useErrorText, useFieldError } from '../../shared/lib/errors';
 import { formatBytes, formatDateTime, formatDuration } from '../../shared/lib/format';
 import { checkIcon, closeIcon, editIcon, refreshIcon } from '../../shared/ui/icons';
@@ -309,6 +310,11 @@ function QueueRow({
       <div className={u.meta}>
         <div className={u.flags}>
           <UploadStatusBadge status={f.status} />
+          {needsFormatAttention(f.format, f.original_name) && (
+            <span className={cx(s.badge, u.tone_warn)} title={t('uploads.format_attention')}>
+              {t('uploads.flag_attention')}
+            </span>
+          )}
           {f.possible_duplicate && <span className={cx(s.badge, u.tone_warn)}>{t('uploads.flag_possible')}</span>}
           {f.quality_upgrade && <span className={cx(s.badge, u.tone_info)}>{t('uploads.flag_quality')}</span>}
           {f.matched_album_id ? (