feat(queue): show playback source in tech strip with preload tracking

Add source badges for offline, cache, and stream playback in the queue tech line, including localized tooltips across shipped locales.

Track Rust preload-ready events by stream track id and latch the selected source per track, with dev logs to debug preload/source mismatches during next-track handoff.

src/store/playerStore.ts

@@ -4,7 +4,7 @@ import { invoke } from '@tauri-apps/api/core';
 import { listen } from '@tauri-apps/api/event';
 import { showToast } from '../utils/toast';
 import { buildCoverArtUrl, buildStreamUrl, getPlayQueue, savePlayQueue, reportNowPlaying, scrobbleSong, SubsonicSong, getSong, getRandomSongs, getSimilarSongs2, getTopSongs, InternetRadioStation, setRating } from '../api/subsonic';
-import { resolvePlaybackUrl } from '../utils/resolvePlaybackUrl';
+import { resolvePlaybackUrl, streamUrlTrackId, getPlaybackSourceKind, type PlaybackSourceKind } from '../utils/resolvePlaybackUrl';
 import { setDeferHotCachePrefetch } from '../utils/hotCacheGate';
 import { lastfmScrobble, lastfmUpdateNowPlaying, lastfmLoveTrack, lastfmUnloveTrack, lastfmGetTrackLoved, lastfmGetAllLovedTracks } from '../api/lastfm';
 import { useAuthStore } from './authStore';
@@ -113,6 +113,13 @@ async function buildInfiniteQueueCandidates(
 interface PlayerState {
   currentTrack: Track | null;
   currentRadio: InternetRadioStation | null;
+  /** Latches the source used to start the currently playing track. */
+  currentPlaybackSource: PlaybackSourceKind | null;
+  /**
+   * Subsonic track id for which `audio_preload` finished into the engine RAM slot (see `audio:preload-ready`).
+   * Cleared after a successful `audio_play` consumed that preload, or when starting another track.
+   */
+  enginePreloadedTrackId: string | null;
   queue: Track[];
   queueIndex: number;
   isPlaying: boolean;
@@ -465,6 +472,16 @@ function handleAudioProgress(current_time: number, duration: number) {
     // Byte pre-download — runs early so bytes are cached by chain time.
     if ((shouldBytePreload || shouldBytePreloadForGaplessBackup) && nextTrack.id !== bytePreloadingId) {
       bytePreloadingId = nextTrack.id;
+      if (import.meta.env.DEV) {
+        console.info('[psysonic][preload-request]', {
+          nextTrackId: nextTrack.id,
+          nextUrl,
+          shouldBytePreload,
+          shouldBytePreloadForGaplessBackup,
+          remaining,
+          gaplessEnabled,
+        });
+      }
       invoke('audio_preload', { url: nextUrl, durationHint: nextTrack.duration }).catch(() => {});
     }
 
@@ -627,6 +644,20 @@ export function initAudioListeners(): () => void {
     listen<void>('audio:ended', () => handleAudioEnded()),
     listen<string>('audio:error', ({ payload }) => handleAudioError(payload)),
     listen<number>('audio:track_switched', ({ payload }) => handleAudioTrackSwitched(payload)),
+    listen<string>('audio:preload-ready', ({ payload }) => {
+      const tid = streamUrlTrackId(payload);
+      if (import.meta.env.DEV) {
+        console.info('[psysonic][preload-ready]', {
+          payload,
+          parsedTrackId: tid,
+          prevEnginePreloadedTrackId: usePlayerStore.getState().enginePreloadedTrackId,
+        });
+      }
+      if (tid) usePlayerStore.setState({ enginePreloadedTrackId: tid });
+      else if (import.meta.env.DEV) {
+        console.warn('[psysonic][preload-ready] could not parse track id from payload URL');
+      }
+    }),
   ];
 
   // Sync Last.fm loved tracks cache on startup.
@@ -804,6 +835,8 @@ export const usePlayerStore = create<PlayerState>()(
     (set, get) => ({
       currentTrack: null,
       currentRadio: null,
+      currentPlaybackSource: null,
+      enginePreloadedTrackId: null,
       queue: [],
       queueIndex: 0,
       isPlaying: false,
@@ -915,7 +948,15 @@ export const usePlayerStore = create<PlayerState>()(
         }
         isAudioPaused = false;
         if (seekDebounce) { clearTimeout(seekDebounce); seekDebounce = null; } seekTarget = null;
-        set({ isPlaying: false, progress: 0, buffered: 0, currentTime: 0, currentRadio: null });
+        set({
+          isPlaying: false,
+          progress: 0,
+          buffered: 0,
+          currentTime: 0,
+          currentRadio: null,
+          currentPlaybackSource: null,
+          enginePreloadedTrackId: null,
+        });
       },
 
       // ── playRadio ────────────────────────────────────────────────────────────
@@ -946,6 +987,7 @@ export const usePlayerStore = create<PlayerState>()(
         set({
           currentRadio: station,
           currentTrack: null,
+          currentPlaybackSource: null,
           queue: [],
           queueIndex: 0,
           isPlaying: true,
@@ -986,6 +1028,25 @@ export const usePlayerStore = create<PlayerState>()(
         const newQueue = queue ?? state.queue;
         const idx = newQueue.findIndex(t => t.id === track.id);
 
+        const authState = useAuthStore.getState();
+        const url = resolvePlaybackUrl(track.id, authState.activeServerId ?? '');
+        const preloadedTrackId = get().enginePreloadedTrackId;
+        const keepPreloadHint = preloadedTrackId === track.id;
+        const playbackSourceHint = getPlaybackSourceKind(
+          track.id,
+          authState.activeServerId ?? '',
+          keepPreloadHint ? track.id : null,
+        );
+        if (import.meta.env.DEV) {
+          console.info('[psysonic][playTrack-source]', {
+            trackId: track.id,
+            resolvedUrl: url,
+            preloadedTrackId,
+            keepPreloadHint,
+            playbackSourceHint,
+          });
+        }
+
         // Set state immediately so the UI updates before the download completes.
         // currentRadio: null ensures the PlayerBar switches out of radio mode right away.
         set({
@@ -999,9 +1060,10 @@ export const usePlayerStore = create<PlayerState>()(
           scrobbled: false,
           lastfmLoved: false,
           isPlaying: true, // optimistic — reverted on error
+          currentPlaybackSource: playbackSourceHint,
+          enginePreloadedTrackId: keepPreloadHint ? track.id : null,
         });
 
-        const authState = useAuthStore.getState();
         if (
           prevTrack
           && prevTrack.id !== track.id
@@ -1015,7 +1077,6 @@ export const usePlayerStore = create<PlayerState>()(
           );
         }
         setDeferHotCachePrefetch(true);
-        const url = resolvePlaybackUrl(track.id, authState.activeServerId ?? '');
         const replayGainDb = authState.replayGainEnabled
           ? (authState.replayGainMode === 'album' ? (track.replayGainAlbumDb ?? track.replayGainTrackDb) : track.replayGainTrackDb) ?? null
           : null;
@@ -1030,16 +1091,23 @@ export const usePlayerStore = create<PlayerState>()(
           fallbackDb: authState.replayGainFallbackDb,
           manual,
           hiResEnabled: authState.enableHiRes,
-        }).catch((err: unknown) => {
-          if (playGeneration !== gen) return;
-          setDeferHotCachePrefetch(false);
-          console.error('[psysonic] audio_play failed:', err);
-          set({ isPlaying: false });
-          setTimeout(() => {
+        })
+          .then(() => {
             if (playGeneration !== gen) return;
-            get().next(false);
-          }, 500);
-        });
+            if (keepPreloadHint) {
+              usePlayerStore.setState({ enginePreloadedTrackId: null });
+            }
+          })
+          .catch((err: unknown) => {
+            if (playGeneration !== gen) return;
+            setDeferHotCachePrefetch(false);
+            console.error('[psysonic] audio_play failed:', err);
+            set({ isPlaying: false });
+            setTimeout(() => {
+              if (playGeneration !== gen) return;
+              get().next(false);
+            }, 500);
+          });
 
         // Report Now Playing to Navidrome (for Live/getNowPlaying) + Last.fm
         const { nowPlayingEnabled: npEnabled, scrobblingEnabled: lfmEnabled, lastfmSessionKey: lfmKey } = useAuthStore.getState();