Show operator preview link on admin request page when both songs uploaded

templates/admin/request.html

@@ -174,6 +174,7 @@
     <!-- Section 4: Notify customer -->
     <div class="section">
       <h2>3. Notify Customer</h2>
+      <!-- Preview link shown to operator after songs are uploaded. -->
       <p>
         Preview email:
         {% if req.preview_sent_at %}
@@ -187,6 +188,13 @@
         <input type="hidden" name="action" value="notify_customer">
         <button type="submit" {% if not (req.song_a_path and req.song_b_path) %}disabled{% endif %}>Send Preview Link</button>
       </form>
+
+      {% if req.song_a_path and req.song_b_path %}
+      <p style="margin-top:.8rem">
+        Operator preview link:
+        <a href="{{ url_for('play', token=req.player_token) }}" target="_blank" rel="noopener noreferrer">Open customer player in new tab →</a>
+      </p>
+      {% endif %}
     </div>
 
     <!-- Section 5: Payment & delivery -->