Sync wishlist re-add: carry the cover image through (real parity)

The re-add showed no album/single art. Cause: reconstruct returned the full track
from tracks_json AS-IS — and some syncs store tracks_json lean (no album.images),
so the re-added wishlist entry had an empty album.images even though the track's
cover was sitting right there in the track_result's image_url.

Fix: always backfill album.images from the track_result's image_url when the album
has none (and copy the dict so tracks_json isn't mutated). Real album art is kept
when present; the 250px thumb only fills a gap. Verified against a real sync row in
all three cases (full / lean tracks_json / no tracks_json) — album.images now
populated in every one. The wishlist card reads album.images, so the cover shows.

core/sync/wishlist_readd.py

@@ -35,33 +35,49 @@ def reconstruct_sync_track_data(
     sid = str(tr.get('source_track_id') or '')
     tracks = tracks or []
 
-    # Prefer the full original track: same index if its id matches, else search by id.
-    full = None
+    # Base: the FULL original track (best fidelity — full album object, ids, source,
+    # artists) by index if its id matches, else by id search. Copied so we never
+    # mutate the caller's tracks list.
+    base: Optional[Dict[str, Any]] = None
     if 0 <= track_index < len(tracks):
         cand = tracks[track_index]
         if isinstance(cand, dict) and (not sid or str(cand.get('id') or '') == sid):
-            full = cand
-    if full is None and sid:
-        full = next(
+            base = dict(cand)
+    if base is None and sid:
+        match = next(
             (t for t in tracks if isinstance(t, dict) and str(t.get('id') or '') == sid),
             None,
         )
-    if isinstance(full, dict) and full.get('id'):
-        return full
+        if match is not None:
+            base = dict(match)
 
-    # Fallback: rebuild from the track_result fields (id required).
-    if not sid:
-        return None
-    album: Dict[str, Any] = {'name': tr.get('album') or ''}
-    if tr.get('image_url'):
-        album['images'] = [{'url': tr['image_url']}]
-    return {
-        'id': sid,
-        'name': tr.get('name') or '',
-        'artists': [{'name': tr.get('artist') or ''}],
-        'album': album,
-        'duration_ms': tr.get('duration_ms') or 0,
-    }
+    # No full track in the cache — rebuild a minimal dict from the track_result.
+    if not (isinstance(base, dict) and base.get('id')):
+        if not sid:
+            return None
+        base = {
+            'id': sid,
+            'name': tr.get('name') or '',
+            'artists': [{'name': tr.get('artist') or ''}],
+            'album': {'name': tr.get('album') or ''},
+            'duration_ms': tr.get('duration_ms') or 0,
+        }
+
+    # Ensure the cover carries through. The wishlist display reads
+    # spotify_data.album.images; tracks_json is sometimes stored WITHOUT images, so
+    # backfill from the track_result's image_url (the album art the sync extracted)
+    # whenever the album has none. This is what makes the re-add reach full parity
+    # with the original auto-add's appearance.
+    album = base.get('album')
+    if not isinstance(album, dict):
+        album = {'name': base.get('name', '')}
+    else:
+        album = dict(album)
+    img = tr.get('image_url')
+    if img and not album.get('images'):
+        album['images'] = [{'url': img}]
+    base['album'] = album
+    return base
 
 
 __all__ = ["reconstruct_sync_track_data"]

tests/test_sync_wishlist_readd.py

@@ -29,8 +29,35 @@ def test_prefers_full_original_track_by_index():
     trs = [_tr(0, "sp_a"), _tr(1, "sp_b")]
     tracks = [_full("sp_a"), _full("sp_b", name="Other")]
     out = reconstruct_sync_track_data(trs, tracks, 1)
-    assert out is tracks[1]                       # exact original (full album+images)
-    assert out["album"]["images"][0]["url"] == "http://cdn/cover.jpg"
+    assert out["id"] == "sp_b"                            # the full original track
+    assert out["album"]["images"][0]["url"] == "http://cdn/cover.jpg"   # its own art kept
+    assert out is not tracks[1]                          # a copy, not the source entry
+
+
+def test_backfills_album_image_when_full_track_has_none():
+    # THE BUG: tracks_json stored without album.images, but the track_result has the
+    # cover. The re-add must carry the image through (parity with the auto-add).
+    trs = [_tr(0, "sp_a", image_url="http://img/cover250.jpg")]
+    tracks = [_full("sp_a", with_images=False)]           # full data but NO images
+    out = reconstruct_sync_track_data(trs, tracks, 0)
+    assert out["id"] == "sp_a"
+    assert out["album"]["images"] == [{"url": "http://img/cover250.jpg"}]
+
+
+def test_full_track_with_images_is_not_overwritten():
+    # When the cached track already has real album art, keep it (don't downgrade to
+    # the 250px track_result thumb).
+    trs = [_tr(0, "sp_a", image_url="http://img/thumb.jpg")]
+    tracks = [_full("sp_a", with_images=True)]
+    out = reconstruct_sync_track_data(trs, tracks, 0)
+    assert out["album"]["images"][0]["url"] == "http://cdn/cover.jpg"   # original kept
+
+
+def test_does_not_mutate_source_tracks_list():
+    trs = [_tr(0, "sp_a", image_url="http://img/x.jpg")]
+    tracks = [_full("sp_a", with_images=False)]
+    reconstruct_sync_track_data(trs, tracks, 0)
+    assert "images" not in tracks[0]["album"]            # source untouched
 
 
 def test_matches_by_id_when_index_misaligns():