fix: Spotify-style shuffle — fixed queue order, not random-each-skip

- playQueue: unified shuffle for both web and Android — pre-shuffles the
  songs array with the tapped song pinned first, saves _origQueue for restore.
  Passes S.qIdx (0 when shuffled) to NSBridge.setQueue instead of startIdx.
- _computeNextIdx: removed the random-pick shuffle branch entirely.
  Since the queue is already shuffled, sequential traversal IS the shuffle order.
- toggleShuffle: removed !HAS_BRIDGE guard so queue reorder runs on Android too.
  Re-sends reordered queue to ExoPlayer so native order stays in sync with JS.
  Removed setShuffleMode call (we manage order ourselves via pre-shuffled array).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/player.js

@@ -359,12 +359,9 @@ export function playQueue(songs, startIdx) {
   _radioFilling = false; // cancel any in-flight radio fill for the old queue
   S._origQueue = null;
   _histClear();
-  // On Android with shuffle on, start at a random position so we don't always
-  // begin at index 0 (the first album/playlist track).
-  if (HAS_BRIDGE && S.shuffle && songs.length > 1) {
-    startIdx = Math.floor(Math.random() * songs.length);
-  }
-  if (!HAS_BRIDGE && S.shuffle && songs.length > 1) {
+  // Spotify-style shuffle: build a fixed shuffled order once, pin the tapped song first.
+  // Applies to both web and Android — queue is traversed sequentially in this fixed order.
+  if (S.shuffle && songs.length > 1) {
     const start = songs[startIdx];
     const rest  = songs.filter((_, i) => i !== startIdx).sort(() => Math.random() - 0.5);
     S._origQueue = songs.map(s => ({...s}));
@@ -387,7 +384,7 @@ export function playQueue(songs, startIdx) {
     // @JavascriptInterface call (which blocks the JS thread while Java
     // parses the JSON and creates MediaItems).
     requestAnimationFrame(() => {
-      try { window.NSBridge.setQueue(trackListJson, startIdx, true); }
+      try { window.NSBridge.setQueue(trackListJson, S.qIdx, true); }
       catch (e) { console.warn('NSBridge.setQueue failed', e); }
       // fillRadioQueue AFTER setQueue so addToQueue lands in the new native queue,
       // not the old one that setQueue is about to wipe.
@@ -655,11 +652,7 @@ export function setPlayIcon(playing) {
 
 function _computeNextIdx() {
   if (S.repeat === 'one') return S.qIdx;
-  if (S.shuffle && S.queue.length > 1) {
-    let n = S.qIdx;
-    while (n === S.qIdx) n = Math.floor(Math.random() * S.queue.length);
-    return n;
-  }
+  // No special shuffle case — queue is already in shuffled order when S.shuffle is on.
   if (S.qIdx + 1 < S.queue.length) return S.qIdx + 1;
   if (S.repeat === 'all') return 0;
   return -1;
@@ -759,7 +752,7 @@ export function _applyShuffleRepeat() {
 export function toggleShuffle() {
   S.shuffle = !S.shuffle;
   localStorage.setItem('ns_shuffle', S.shuffle ? '1' : '0');
-  if (!HAS_BRIDGE && S.queue.length > 1) {
+  if (S.queue.length > 1) {
     if (S.shuffle) {
       const cur  = S.queue[S.qIdx];
       S._origQueue = [...S.queue];
@@ -774,9 +767,14 @@ export function toggleShuffle() {
       S.qIdx = idx >= 0 ? idx : 0;
     }
     renderQueue();
+    // Re-send the reordered queue to native so ExoPlayer's order matches JS.
+    if (HAS_BRIDGE) {
+      const tl = JSON.stringify(buildTrackList());
+      try { window.NSBridge.setQueue(tl, S.qIdx, _nativePlaying); }
+      catch(e) { console.warn('NSBridge.setQueue failed', e); }
+    }
   }
   _applyShuffleRepeat();
-  if (HAS_BRIDGE) _nsBridge('setShuffleMode', S.shuffle);
 }
 
 export function toggleRepeat() {