fix(media): quote forwarded cookie headers

Keep yt-dlp config values intact and require explicit media metadata before downloads can start.

src/utils/addDownloadMetadata.test.ts

@@ -187,11 +187,15 @@ describe('add download metadata workflow', () => {
     expect(updated[0]).toBe(current);
   });
 
-  it('allows ready and failed rows but blocks loading and invalid rows', () => {
+  it('allows normal-download fallback but blocks unresolved explicit media', () => {
     expect(canSubmitMetadataRows([
       row(),
       row({ id: 'fallback', status: 'metadata-error' })
     ])).toBe(true);
+    expect(canSubmitMetadataRows([
+      row(),
+      row({ id: 'media-fallback', status: 'metadata-error', isMedia: true })
+    ])).toBe(false);
     expect(canSubmitMetadataRows([row({ status: 'loading' })])).toBe(false);
     expect(canSubmitMetadataRows([row({ status: 'invalid' })])).toBe(false);
   });
@@ -246,6 +250,9 @@ describe('add download metadata workflow', () => {
     expect(metadataSummaryMessage([
       row({ status: 'metadata-error' })
     ])).toContain('can still be added');
+    expect(metadataSummaryMessage([
+      row({ status: 'metadata-error', isMedia: true })
+    ])).toContain('Refresh metadata before adding');
     expect(metadataSummaryMessage([
       row({ status: 'invalid' })
     ])).toContain('Correct or remove 1 invalid URL');

src/utils/addDownloadMetadata.ts

@@ -146,7 +146,10 @@ export const refreshFailedMetadataRows = (
 
 export const canSubmitMetadataRows = (rows: AddDownloadDraftRow[]): boolean =>
   rows.length > 0
-  && rows.every(row => row.status === 'ready' || row.status === 'metadata-error');
+  && rows.every(row =>
+    row.status === 'ready'
+    || (!row.isMedia && row.status === 'metadata-error')
+  );
 
 export const mediaFormatSelectorForRow = (
   row: AddDownloadDraftRow
@@ -203,7 +206,11 @@ export const metadataSummaryMessage = (rows: AddDownloadDraftRow[]): string => {
   }
 
   const failed = rows.filter(row => row.status === 'metadata-error').length;
+  const failedMedia = rows.filter(row => row.status === 'metadata-error' && row.isMedia).length;
   const ready = rows.filter(row => row.status === 'ready').length;
+  if (failedMedia > 0) {
+    return `Media metadata is unavailable for ${failedMedia} item${failedMedia === 1 ? '' : 's'}. Refresh metadata before adding.`;
+  }
   if (failed === rows.length) {
     return 'Metadata is unavailable. Downloads can still be added using fallback details.';
   }