fix(purchases): restructure download paths to Artist/Album [FORMAT][Quality]/track

Embeds quality in album folder name instead of subfolder, so each
quality variant appears as a separate album in the local library.
Adds download error toast and fixes format labels to bracket notation.
Closes #116

src-tauri/src/commands_v2.rs

@@ -10614,7 +10614,7 @@ fn v2_purchase_target_path(
     ext: &str,
 ) -> PathBuf {
     let artist_dir = crate::offline_cache::metadata::sanitize_filename(artist_name);
-    let album_dir = crate::offline_cache::metadata::sanitize_filename(album_title);
+    let album_clean = crate::offline_cache::metadata::sanitize_filename(album_title);
     let title_clean = crate::offline_cache::metadata::sanitize_filename(track_title);
 
     let file_name = if track_number > 0 {
@@ -10623,13 +10623,18 @@ fn v2_purchase_target_path(
         format!("{}.{}", title_clean, ext)
     };
 
-    let mut path = PathBuf::from(destination)
+    // Embed quality in album folder name: "Album [FLAC][24-bit,96kHz]"
+    let album_dir = if !quality_dir.is_empty() {
+        let quality_clean = crate::offline_cache::metadata::sanitize_filename(quality_dir);
+        format!("{} {}", album_clean, quality_clean)
+    } else {
+        album_clean
+    };
+
+    PathBuf::from(destination)
         .join(artist_dir)
-        .join(album_dir);
-    if !quality_dir.is_empty() {
-        path = path.join(crate::offline_cache::metadata::sanitize_filename(quality_dir));
-    }
-    path.join(file_name)
+        .join(album_dir)
+        .join(file_name)
 }
 
 fn v2_apply_purchase_download_flags(
@@ -11000,7 +11005,7 @@ pub async fn v2_purchases_get_formats(
     if album.hires && album.maximum_sampling_rate.unwrap_or(0.0) > 96.0 {
         formats.push(V2PurchaseFormatOption {
             id: 27,
-            label: "FLAC 24-bit / 192 kHz".to_string(),
+            label: "[FLAC][24-bit,192kHz]".to_string(),
             bit_depth: Some(24),
             sampling_rate: Some(192.0),
         });
@@ -11009,7 +11014,7 @@ pub async fn v2_purchases_get_formats(
     if album.hires {
         formats.push(V2PurchaseFormatOption {
             id: 7,
-            label: "FLAC 24-bit / 96 kHz".to_string(),
+            label: "[FLAC][24-bit,96kHz]".to_string(),
             bit_depth: Some(24),
             sampling_rate: Some(96.0),
         });
@@ -11017,14 +11022,14 @@ pub async fn v2_purchases_get_formats(
 
     formats.push(V2PurchaseFormatOption {
         id: 6,
-        label: "FLAC 16-bit / 44.1 kHz".to_string(),
+        label: "[FLAC][16-bit,44.1kHz]".to_string(),
         bit_depth: Some(16),
         sampling_rate: Some(44.1),
     });
 
     formats.push(V2PurchaseFormatOption {
         id: 5,
-        label: "MP3 320 kbps".to_string(),
+        label: "[MP3][320kbps]".to_string(),
         bit_depth: None,
         sampling_rate: None,
     });

src/lib/components/views/PurchasesView.svelte

@@ -436,6 +436,7 @@
       formatPickerAnchor = { top: rect.bottom + 4, right: window.innerWidth - rect.right };
     } catch (err) {
       console.error('Track download error:', err);
+      showToast($t('purchases.errors.downloadFailed'), 'error');
     }
   }
 
@@ -1865,7 +1866,7 @@
   }
 
   .track-row.downloaded {
-    opacity: 0.6;
+    opacity: 0.75;
   }
 
   /* Format picker popup */

src/lib/i18n/locales/de.json

@@ -1719,7 +1719,8 @@
     "regionNotice": "Die Verfügbarkeit von Käufen hängt von deinem Qobuz-Konto und deiner Region ab. Wenn es nicht verfügbar ist, kann das erwartet sein.",
     "errors": {
       "noAlbum": "Download nicht moeglich: Titel hat kein zugehoeriges Album.",
-      "noFormats": "Keine Download-Formate fuer diesen Titel verfuegbar."
+      "noFormats": "Keine Download-Formate fuer diesen Titel verfuegbar.",
+      "downloadFailed": "Download konnte nicht gestartet werden. Bitte erneut versuchen."
     }
   },
   "playlistManager": {

src/lib/i18n/locales/en.json

@@ -1900,7 +1900,8 @@
     "regionNotice": "Purchases availability depends on your Qobuz account and region. If unavailable, this may be expected.",
     "errors": {
       "noAlbum": "Cannot download: track has no associated album.",
-      "noFormats": "No download formats available for this track."
+      "noFormats": "No download formats available for this track.",
+      "downloadFailed": "Failed to start download. Please try again."
     }
   },
   "yourMixes": {

src/lib/i18n/locales/es.json

@@ -1900,7 +1900,8 @@
     "regionNotice": "La disponibilidad de Compras depende de tu cuenta y region de Qobuz. Si no aparece disponible, puede ser esperado.",
     "errors": {
       "noAlbum": "No se puede descargar: la pista no tiene album asociado.",
-      "noFormats": "No hay formatos de descarga disponibles para esta pista."
+      "noFormats": "No hay formatos de descarga disponibles para esta pista.",
+      "downloadFailed": "Error al iniciar la descarga. Intenta de nuevo."
     }
   },
   "yourMixes": {

src/lib/i18n/locales/fr.json

@@ -1719,7 +1719,8 @@
     "regionNotice": "La disponibilité des achats dépend de votre compte Qobuz et de votre région. Si ce n'est pas disponible, cela peut être normal.",
     "errors": {
       "noAlbum": "Telechargement impossible : la piste n'a pas d'album associe.",
-      "noFormats": "Aucun format de telechargement disponible pour cette piste."
+      "noFormats": "Aucun format de telechargement disponible pour cette piste.",
+      "downloadFailed": "Impossible de demarrer le telechargement. Veuillez reessayer."
     }
   },
   "playlistManager": {

src/lib/stores/purchaseDownloadStore.ts

@@ -81,25 +81,14 @@ export function startAlbumDownload(
 
 /**
  * Extract the album-level folder from a downloaded file path.
- * Download structure: destination/artist/album/[qualityDir/]track.ext
- * We want: destination/artist/album/
+ * Download structure: destination/artist/album [quality]/track.ext
+ * We want: destination/artist/album [quality]/
  */
-function albumFolderFromFilePath(filePath: string, hasQualityDir: boolean): string {
-  // Remove filename
+function albumFolderFromFilePath(filePath: string): string {
+  // Remove filename to get the album directory
   let lastSep = filePath.lastIndexOf('/');
   if (lastSep < 0) lastSep = filePath.lastIndexOf('\\');
-  let dir = lastSep >= 0 ? filePath.substring(0, lastSep) : filePath;
-
-  // If there's a quality subdirectory, go up one more level
-  if (hasQualityDir) {
-    let prevSep = dir.lastIndexOf('/');
-    if (prevSep < 0) prevSep = dir.lastIndexOf('\\');
-    if (prevSep >= 0) {
-      dir = dir.substring(0, prevSep);
-    }
-  }
-
-  return dir;
+  return lastSep >= 0 ? filePath.substring(0, lastSep) : filePath;
 }
 
 async function executeAlbumDownload(
@@ -144,7 +133,7 @@ async function executeAlbumDownload(
       // so "Add to Library" adds only this album, not the entire root.
       if (!albumFolderResolved) {
         albumFolderResolved = true;
-        const albumFolder = albumFolderFromFilePath(filePath, qualityDir.length > 0);
+        const albumFolder = albumFolderFromFilePath(filePath);
         updateAlbumState(albumId, (state) => ({
           ...state,
           destination: albumFolder,