feat(music): prefetch 2 tracks ahead instead of 1

Complements the WebRTC auto-reconnect: a track already sitting in
blobCacheRef needs no live connection to play, so whatever was fetched
before a screen lock started plays through it regardless of what the
transport is doing during the lock. One track of runway was often shorter
than the lock itself; two buys more of it. MAX_CACHED_BLOBS (3) already
covers the currently-playing track plus these two, so no cache-size change
needed.

1 files changed, 16 insertions, 4 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/music-player.js b/packages/meshbay-hub/src/meshbay_hub/static/music-player.js
index 73cae27..7fdc74e 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/music-player.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/music-player.js
@@ -255,12 +255,24 @@ function MusicPlayerBar({ transportRef, gekRef, queue, onClose }) {
     return url;
   }, [transportRef, gekRef, evictOldBlobs]);
 
-  // Silently warms the cache for the next track so pressing "next" doesn't
+  // Silently warms the cache for the next tracks so pressing "next" doesn't
   // visibly wait (musicbay.md §2.2) — best-effort, never surfaces an error.
+  //
+  // Two ahead, not one: a screen lock can cost the transport several minutes
+  // (see the WebRTC auto-reconnect in transport.js — this is the other half
+  // of the same fix). A track already sitting in blobCacheRef needs no
+  // connection at all to play, so whatever got fetched *before* the lock
+  // started plays through it regardless of what the connection is doing —
+  // it just buys more of that runway than fetching only one track ahead did.
+  // MAX_CACHED_BLOBS is sized for exactly this: the one playing plus these two.
+  const PREFETCH_AHEAD = 2;
+
   const prefetchNext = useCallback((fromPos) => {
-    const nextEntry = tracks[order[fromPos + 1]];
-    if (!nextEntry || blobCacheRef.current.has(nextEntry.id)) return;
-    fetchTrackBlob(nextEntry).catch(() => {});
+    for (let ahead = 1; ahead <= PREFETCH_AHEAD; ahead++) {
+      const nextEntry = tracks[order[fromPos + ahead]];
+      if (!nextEntry || blobCacheRef.current.has(nextEntry.id)) continue;
+      fetchTrackBlob(nextEntry).catch(() => {});
+    }
   }, [tracks, order, fetchTrackBlob]);
 
   // (Re)initialize the queue whenever the shell hands over a new one.