feat(ui): add explicit content badge across entire app

Display parental_warning badge (E icon) next to track titles in all
views: TrackRow, QueuePanel, NowPlayingBar, ImmersivePlayer with all
13 visualizer panels, MiniPlayer surfaces, and AlbumDetailView.

Propagate parental_warning field through the full data chain from
Rust backend (qbz-models, queue, commands_v2, session_store, API
server) to frontend stores, adapters, and UI components. Badge uses
CSS mask technique with explicit.svg for theme compatibility.

src-tauri/src/api_server/mod.rs

@@ -979,6 +979,7 @@ async fn play_album(
                     artist_id: t.performer.as_ref().map(|p| p.id),
                     streamable: t.streamable,
                     source: Some("qobuz".to_string()),
+                    parental_warning: t.parental_warning,
                 }
             })
             .collect()

src-tauri/src/commands_v2.rs

@@ -5477,6 +5477,7 @@ fn track_to_queue_track_from_api(track: &crate::api::Track) -> CoreQueueTrack {
         artist_id,
         streamable: track.streamable,
         source: Some("qobuz".to_string()),
+        parental_warning: track.parental_warning,
     }
 }
 
@@ -5604,6 +5605,8 @@ pub struct V2QueueTrack {
     /// Source type: "qobuz", "local", "plex"
     #[serde(default)]
     pub source: Option<String>,
+    #[serde(default)]
+    pub parental_warning: bool,
 }
 
 fn default_streamable() -> bool {
@@ -5627,6 +5630,7 @@ impl From<V2QueueTrack> for crate::queue::QueueTrack {
             artist_id: t.artist_id,
             streamable: t.streamable,
             source: t.source,
+            parental_warning: t.parental_warning,
         }
     }
 }
@@ -5648,6 +5652,7 @@ impl From<crate::queue::QueueTrack> for V2QueueTrack {
             artist_id: t.artist_id,
             streamable: t.streamable,
             source: t.source,
+            parental_warning: t.parental_warning,
         }
     }
 }
@@ -5670,6 +5675,7 @@ impl From<V2QueueTrack> for CoreQueueTrack {
             artist_id: t.artist_id,
             streamable: t.streamable,
             source: t.source,
+            parental_warning: t.parental_warning,
         }
     }
 }
@@ -5691,6 +5697,7 @@ impl From<CoreQueueTrack> for V2QueueTrack {
             artist_id: t.artist_id,
             streamable: t.streamable,
             source: t.source,
+            parental_warning: t.parental_warning,
         }
     }
 }

src-tauri/src/queue/mod.rs

@@ -54,6 +54,9 @@ pub struct QueueTrack {
     /// Optional origin source (e.g. "qobuz", "local", "plex")
     #[serde(default)]
     pub source: Option<String>,
+    /// Parental advisory / explicit content
+    #[serde(default)]
+    pub parental_warning: bool,
 }
 
 fn default_streamable() -> bool {
@@ -759,6 +762,7 @@ mod tests {
             artist_id: None,
             streamable: true,
             source: Some("test".to_string()),
+            parental_warning: false,
         }
     }
 

src-tauri/src/session_store/mod.rs

@@ -29,6 +29,8 @@ pub struct PersistedQueueTrack {
     pub streamable: bool,
     #[serde(default)]
     pub source: Option<String>,
+    #[serde(default)]
+    pub parental_warning: bool,
 }
 
 /// Represents the full persisted session state
@@ -345,6 +347,7 @@ impl SessionStore {
                     artist_id: row.get::<_, Option<i64>>(11)?.map(|v| v as u64),
                     streamable: true, // Default to true for persisted tracks
                     source: row.get(12)?,
+                    parental_warning: false, // Not persisted in DB
                 })
             })
             .map_err(|e| format!("Failed to query queue tracks: {}", e))?