Implement 'call' button

index.html

@@ -14,6 +14,7 @@
       <input type="search" id="filter-search" placeholder="Search…" />
       <button id="btn-clear-filters" hidden>✕ Clear filters</button>
       <span id="status"></span>
+      <button id="btn-call">Call</button>
       <button id="btn-bulk-edit" hidden>⚡ Bulk Edit</button>
       <button id="btn-add-tune" hidden>+ Add tune</button>
       <button id="btn-unlock">🔒 Unlock</button>
@@ -182,6 +183,16 @@
     </div>
   </dialog>
 
+  <!-- ── Call modal ─────────────────────────────────────────── -->
+  <dialog id="call-modal">
+    <div id="call-header">
+      <button id="call-back" hidden>← Back</button>
+      <h2 id="call-title"></h2>
+      <button id="call-close">✕</button>
+    </div>
+    <div id="call-options"></div>
+  </dialog>
+
   <!-- Tooltip for truncated mobile text -->
   <div id="mob-tooltip" hidden></div>