Add support for fusing/unfusing JellyLMS zones into synchronized

multi-room groups, addressed by MAC (derived from the `lms-{mac}` device id).

src-tauri/src/commands/playback_mode.rs

@@ -51,6 +51,22 @@ pub async fn playback_mode_transfer_to_remote(
     manager.0.transfer_to_remote(session_id, position).await
 }
 
+/// Set the transferring flag on the playback mode manager.
+///
+/// Used by the frontend remote->local flow to mark the whole two-step sequence
+/// as a transfer, so `player_play_tracks` starts LOCAL playback instead of
+/// casting back to the remote session it's leaving. Always pair `true` with a
+/// later `false` (including on error) so the flag can't stick.
+#[tauri::command]
+#[specta::specta]
+pub async fn playback_mode_set_transferring(
+    manager: State<'_, PlaybackModeManagerWrapper>,
+    transferring: bool,
+) -> Result<(), String> {
+    manager.0.set_transferring(transferring);
+    Ok(())
+}
+
 /// Transfer playback from remote session back to local device
 ///
 /// Parameters:

src-tauri/src/commands/player/remote.rs

@@ -6,6 +6,7 @@
 use tauri::State;
 
 use super::PlayerStateWrapper;
+use crate::jellyfin::client::LmsSyncGroup;
 
 /// Play items on a remote Jellyfin session (casting)
 #[tauri::command]
@@ -129,3 +130,92 @@ pub async fn remote_session_toggle_mute(
         Err("Jellyfin client not configured".to_string())
     }
 }
+
+// --- JellyLMS multi-room sync groups (fuse / unfuse LMS zones) --------------
+//
+// The frontend addresses LMS players by MAC address, which it derives from a
+// session's device id (`lms-{mac}`). These commands forward to the JellyLMS
+// plugin REST API via the configured JellyfinClient.
+
+/// List current LMS sync groups.
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_get_sync_groups(
+    player: State<'_, PlayerStateWrapper>,
+) -> Result<Vec<LmsSyncGroup>, String> {
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_get_sync_groups().await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}
+
+/// Fuse LMS zones into a sync group. `master_mac` keeps playing and the
+/// `slave_macs` zones join it in sync.
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_create_sync_group(
+    player: State<'_, PlayerStateWrapper>,
+    master_mac: String,
+    slave_macs: Vec<String>,
+) -> Result<(), String> {
+    log::info!("[LmsSync] Fusing zones: master={}, slaves={:?}", master_mac, slave_macs);
+
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_create_sync_group(&master_mac, slave_macs).await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}
+
+/// Remove a single LMS zone from its sync group (decouple one player).
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_unsync_player(
+    player: State<'_, PlayerStateWrapper>,
+    mac: String,
+) -> Result<(), String> {
+    log::info!("[LmsSync] Decoupling zone {}", mac);
+
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_unsync_player(&mac).await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}
+
+/// Dissolve an entire LMS sync group, identified by its master's MAC.
+#[tauri::command]
+#[specta::specta]
+pub async fn lms_dissolve_sync_group(
+    player: State<'_, PlayerStateWrapper>,
+    master_mac: String,
+) -> Result<(), String> {
+    log::info!("[LmsSync] Dissolving group with master {}", master_mac);
+
+    let client_opt = {
+        let controller = player.0.lock().await;
+        controller.jellyfin_client().lock().map_err(|e| e.to_string())?.clone()
+    };
+
+    if let Some(client) = client_opt {
+        client.lms_dissolve_sync_group(&master_mac).await
+    } else {
+        Err("Jellyfin client not configured".to_string())
+    }
+}