refactor: dedup buildTrackList, extract topsong row helper, split romaji to lib

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

src/player.js

@@ -46,9 +46,9 @@ function _nsBridge(method, ...args) {
   try { window.NSBridge[method](...args); } catch(_) {}
 }
 
-// Build the NSBridge Track JSON array from S.queue.
-function buildTrackList() {
-  return S.queue.map(s => ({
+// Convert a single Navidrome song to the NSBridge Track schema.
+function _trackToNative(s) {
+  return {
     id:         s.id,
     url:        streamUrl(s.id),
     title:      s.title  || '',
@@ -56,9 +56,12 @@ function buildTrackList() {
     album:      s.album  || null,
     artworkUrl: s.coverArt ? coverUrl(s.coverArt, 1024) : null,
     durationMs: Math.floor((s.duration || 0) * 1000),
-  }));
+  };
 }
 
+// Build the NSBridge Track JSON array from S.queue.
+const buildTrackList = () => S.queue.map(_trackToNative);
+
 // Push the current JS queue to native whenever S.queue changes (radio top-ups, etc.).
 function _pushQueueIfBridge() {
   if (!HAS_BRIDGE) return;
@@ -73,19 +76,6 @@ export function nativeInsertAt(song, position) {
   try { window.NSBridge.addToQueue(JSON.stringify(_trackToNative(song)), position); } catch(_) {}
 }
 
-// Convert a single Navidrome song to the NSBridge Track schema (used for addToQueue).
-function _trackToNative(s) {
-  return {
-    id:         s.id,
-    url:        streamUrl(s.id),
-    title:      s.title  || '',
-    artist:     s.artist || '',
-    album:      s.album  || null,
-    artworkUrl: s.coverArt ? coverUrl(s.coverArt, 1024) : null,
-    durationMs: Math.floor((s.duration || 0) * 1000),
-  };
-}
-
 // ─── NATIVE → JS CALLBACKS ────────────────────────────────────────────────
 // window.NSPlayer is the surface that MusicService calls back into.
 // Installed here so it exists before onPageFinished fires.