feat(slint): MPRIS album art (mpris:artUrl) — Qobuz pass-through + local file://

Port the Tauri normalizeCoverUrlForMetadata workaround as ArtworkRef::to_mpris_url
(qbz-models): remote Qobuz covers pass through as-is, local-file covers become a
percent-encoded file:// URI (MPRIS clients cannot read bare paths or asset://),
Plex thumbs become a tokenized HTTP URL. Wired into the Slint now-playing push so
the media widget shows album art. The app icon was already fixed via DesktopEntry.

cc

crates/Cargo.lock

@@ -5700,6 +5700,7 @@ dependencies = [
  "serde",
  "serde_json",
  "thiserror 2.0.18",
+ "url",
 ]
 
 [[package]]

crates/qbz-models/Cargo.toml

@@ -21,3 +21,6 @@ thiserror = { workspace = true }
 
 # Time
 chrono = { workspace = true }
+
+# Correct file:// URI building for media-controls art (ArtworkRef::to_mpris_url)
+url = "2"

crates/qbz-models/src/source.rs

@@ -144,6 +144,37 @@ impl ArtworkRef {
             ArtworkRef::PlexThumb { path, .. } => path.is_empty(),
         }
     }
+
+    /// A URL suitable for the MPRIS `mpris:artUrl` property (and other OS media
+    /// controls). Mirrors the Tauri frontend's `normalizeCoverUrlForMetadata`:
+    /// - **Remote** HTTP(S) covers (Qobuz) pass through — clients fetch them.
+    /// - **LocalFile** bare paths become a proper percent-encoded `file://`
+    ///   URI (MPRIS clients cannot read a bare path or an `asset://` URL).
+    /// - **PlexThumb** becomes the tokenized HTTP URL the client can fetch.
+    /// - **Embedded** bytes / **None** have no URL (`None`).
+    pub fn to_mpris_url(&self) -> Option<String> {
+        match self {
+            ArtworkRef::Remote(s) if !s.is_empty() => Some(s.clone()),
+            ArtworkRef::LocalFile(p) if !p.is_empty() => {
+                // Already a file URL? keep it. Otherwise build one (absolute
+                // paths only — `from_file_path` rejects relative, → None).
+                if p.starts_with("file://") {
+                    Some(p.clone())
+                } else {
+                    url::Url::from_file_path(p).ok().map(|u| u.to_string())
+                }
+            }
+            ArtworkRef::PlexThumb {
+                base_url,
+                token,
+                path,
+            } if !path.is_empty() => {
+                let sep = if path.contains('?') { '&' } else { '?' };
+                Some(format!("{base_url}{path}{sep}X-Plex-Token={token}"))
+            }
+            _ => None,
+        }
+    }
 }
 
 impl QueueTrack {

crates/qbz-slint/src/playback.rs

@@ -562,15 +562,16 @@ pub(crate) async fn refresh_now_playing_meta(runtime: &Runtime, weak: &slint::We
     }
 
     // Push to the OS media controls (MPRIS / SMTC / MediaRemote). The app icon
-    // GNOME shows comes from the MPRIS DesktopEntry, not from album art; art_url
-    // (album art) is a later refinement.
+    // GNOME shows comes from the MPRIS DesktopEntry; `art_url` is the album art
+    // (`mpris:artUrl`) — remote Qobuz covers pass through, local covers become a
+    // file:// URI, matching the Tauri `normalizeCoverUrlForMetadata` workaround.
     if let Some(mc) = crate::media_controls::handle() {
         mc.set_metadata(&qbz_media_controls::TrackMeta {
             title: title.clone(),
             artist: artist.clone(),
             album: album.clone(),
             duration: (duration > 0).then(|| std::time::Duration::from_secs(duration as u64)),
-            art_url: None,
+            art_url: artwork.to_mpris_url(),
         });
         mc.set_playback(
             qbz_media_controls::PlaybackStatus::Playing,