fix: iTunes Japanese artist lookup + sort tag editing in info modal

- views.js: skip ASCII word-match when artist name is non-ASCII so Japanese
  artists (e.g. ヨルシカ) resolve correctly to an iTunes artist ID
- index.html + styles.css: collapsible Sort-Tags section in edit modal
- ui.js: pre-fill sort fields from romaji index; include in save body
- novasonic-server.js: accept manual titleSort/artistSort/albumArtistSort/albumSort
  overrides; fall back to auto-computed romaji when not provided

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

index.html

@@ -943,6 +943,15 @@
           <label class="info-edit-label">Tracks ges.<input class="info-edit-input" id="ie-totaltracks" type="number" placeholder="12" min="1"></label>
         </div>
       </div>
+      <details class="ie-sort-details">
+        <summary>Sort-Tags (Japanisch)</summary>
+        <div class="info-edit-fields" style="margin-top:8px">
+          <label class="info-edit-label">Titel-Sort<input class="info-edit-input" id="ie-titlesort" type="text" placeholder="Romaji / Sort-Titel"></label>
+          <label class="info-edit-label">Künstler-Sort<input class="info-edit-input" id="ie-artistsort" type="text" placeholder="Romaji / Sort-Künstler"></label>
+          <label class="info-edit-label">Album-Künstler-Sort<input class="info-edit-input" id="ie-albumartistsort" type="text" placeholder="Romaji / Sort-Album-Künstler"></label>
+          <label class="info-edit-label">Album-Sort<input class="info-edit-input" id="ie-albumsort" type="text" placeholder="Romaji / Sort-Album"></label>
+        </div>
+      </details>
       <div id="info-edit-status" style="font-size:12px;color:var(--text3);padding:0 20px 8px;min-height:18px"></div>
       <div style="display:flex;gap:8px;padding:0 20px 20px">
         <button class="info-close" style="flex:1;margin:0" onclick="toggleInfoEdit()">Abbrechen</button>