fix(ui): address review feedback on Spanish translations

- Use 'Ganancia del álbum' (with article 'del') for consistency with the existing pattern in line 624 ('album': 'Ganancia del álbum') and 'Artista del álbum'. Thanks @gemini-code-assist for the catch.
- Revert 'playlists' and 'sharedPlaylists' to keep the loanword 'Playlist(s)' which is the form actually used by Spanish-speaking music app users (Spotify ES, etc.) and matches existing usage elsewhere in this same file (e.g. line 48 'Agregar a la playlist').

Signed-off-by: Daniel Banariba <banaribad@gmail.com>

resources/i18n/es.json

@@ -35,7 +35,7 @@
         "rawTags": "Etiquetas sin procesar",
         "bitDepth": "Profundidad de bits",
         "sampleRate": "Frecuencia de muestreo",
-        "albumGain": "Ganancia de álbum",
+        "albumGain": "Ganancia del álbum",
         "trackGain": "Ganancia de pista",
         "missing": "Faltante",
         "libraryName": "Biblioteca",
@@ -627,8 +627,8 @@
     },
     "albumList": "Álbumes",
     "about": "Acerca de",
-    "playlists": "Listas de reproducción",
-    "sharedPlaylists": "Listas de reproducción compartidas",
+    "playlists": "Playlists",
+    "sharedPlaylists": "Playlists Compartidas",
     "librarySelector": {
       "allLibraries": "Todas las bibliotecas (%{count})",
       "multipleLibraries": "%{selected} de %{total} bibliotecas",