Credit this port in the web UI footer

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

firmware/uniclock/ESP32_UniClock2/data/index.html

@@ -418,6 +418,7 @@
         <div class="separator"></div>
         <div class="footer">
             © 2020-22 Peter Gautier<span>-</span><a href="mailto: gautier.p62@gmail.com">gautier.p62@gmail.com</a><br>
+            Modified by Claude for the RetroModding NixieIN12v2 clock<span>-</span><a href="https://mangavalk.com/mangavalk/nixie-clock" target="_blank">mangavalk.com/mangavalk/nixie-clock</a><br>
             <div id="version" class="info" pagemenu="settings"></div>
         </div>
     </div>