chore(release): 0.57.0 — downloads & channels fixpack

Downloads UI quick wins, categorized download-failure dialog, channel full-history + honest
stored/total count, press-and-hold + inline-editable priority, iOS background audio on the shared
watch page, and Facebook OG image-dimension fix. Adds migration 0061 (download_jobs.error_code).

VERSION

@@ -1 +1 @@
-0.56.0
+0.57.0

frontend/src/lib/releaseNotes.ts

@@ -14,6 +14,22 @@ export interface ReleaseEntry {
 }
 
 export const RELEASE_NOTES: ReleaseEntry[] = [
+  {
+    version: "0.57.0",
+    date: "2026-07-28",
+    summary:
+      "Downloads and channels polish — clearer download failures, a friendlier share flow, richer channel controls, and background audio for shared videos on iPhone/iPad.",
+    features: [
+      "Downloads: the page now opens on the Queue tab, the library shows when each item was downloaded, the Share dialog opens with a ready-to-copy link already created (all the other link options stay available), and you can paste a link from the clipboard with one tap.",
+      "Downloads: a failed item now explains WHY in a readable message — video unavailable, sign-in required, region-blocked, no downloadable format, and so on — with the raw technical detail one click away and a Retry offered when the failure looks temporary.",
+      "Channels: a channel's page now shows how many of its videos are stored versus its true total, with a “Full history” button to pull the rest. The priority arrows repeat (and speed up) while held instead of one click at a time, the value sits where the cursor can't cover it, and you can click the number to type any priority directly — negatives included.",
+      "Sharing: a shared video keeps playing audio in the background on iPhone/iPad (like YouTube) when you leave the browser.",
+    ],
+    fixes: [
+      "Downloads: thumbnails that had gone missing (when the original video was deleted or its link expired) now fall back to the saved poster instead of showing a broken image.",
+      "Sharing: shared-link previews now reliably include the thumbnail when pasted into Facebook Messenger on the desktop web (dimensions are declared so its scraper shows the image on the first fetch).",
+    ],
+  },
   {
     version: "0.56.0",
     date: "2026-07-28",