Fix M17: statusByUrl picks highest-priority status for duplicate URLs

LibraryView mapped url -> status by last-write, so when a URL had multiple
queue entries ("Download anyway"), the row reflected whichever item was
iterated last. Added a STATUS_PRIORITY ranking (completed > downloading >
queued > saved > paused > error > canceled) and keep the highest-priority
status per URL, so a row shows the most meaningful state of that video.

typecheck + 242 tests + eslint green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CODE-AUDIT.md

@@ -272,7 +272,7 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   fallback is dependency-free (no Fluent/theme provider — the crash may have come from that tree), logs via
   `componentDidCatch`, shows the error message, and offers a Reload button (`window.location.reload()`;
   persisted data lives in main, so nothing is lost).*
-- [ ] **M17 — `statusByUrl` collapses duplicate URLs.** LibraryView maps URL→status into one
+- [x] **M17 — `statusByUrl` collapses duplicate URLs.** LibraryView maps URL→status into one
   `Map`; with "Download anyway" duplicates, a row can reflect the wrong item's state.
 - [ ] **M18 — Audio "quality" presets hard-code MP3.** `QUALITY_OPTIONS.audio` labels ("Best
   (MP3)", "320 kbps") are shown even when `downloadOptions.audioFormat` is opus/flac/wav, so the

src/renderer/src/components/LibraryView.tsx

@@ -59,6 +59,19 @@ type LibRow =
 /** Above this many flattened rows, the item list switches to a virtualized panel. */
 const VIRTUALIZE_AT = 100
 
+// When a URL appears more than once in the queue ("Download anyway" duplicates),
+// the library row should reflect the most meaningful state: a finished copy wins,
+// then anything in flight, then terminal failures (M17).
+const STATUS_PRIORITY: Record<DownloadStatus, number> = {
+  completed: 6,
+  downloading: 5,
+  queued: 4,
+  saved: 3,
+  paused: 2,
+  error: 1,
+  canceled: 0
+}
+
 const useStyles = makeStyles({
   root: { display: 'flex', flexDirection: 'column', gap: '18px' },
   sub: { color: tokens.colorNeutralForeground3 },
@@ -308,7 +321,13 @@ export function LibraryView(): React.JSX.Element {
   // Live per-URL queue status so a video row reflects its real download state.
   const statusByUrl = useMemo(() => {
     const m = new Map<string, DownloadStatus>()
-    for (const d of downloadItems) m.set(d.url, d.status)
+    for (const d of downloadItems) {
+      const prev = m.get(d.url)
+      // Keep the highest-priority status when a URL has duplicate queue entries.
+      if (prev === undefined || STATUS_PRIORITY[d.status] > STATUS_PRIORITY[prev]) {
+        m.set(d.url, d.status)
+      }
+    }
     return m
   }, [downloadItems])