Sync pydevices hero mask fix from dotgithub (square, not round)

Author: bdbarnett

pydevices/index.html

@@ -34,7 +34,7 @@ <h1>pydevices — Hardware Abstraction Layer & Core Contract.</h1>
       </div>
     </div>
     <div class="hero-canvas-wrap" data-hero-canvas="hero_canvas" data-hero-app="signal_gen" data-hero-deps="pydevices,pydevices-lvgl" data-hero-app-url="https://PyDevices.github.io/assets/apps/signal_gen.py">
-      <div class="hero-canvas-circle">
+      <div class="hero-canvas-square">
         <div class="hero-canvas-loader">
           <div class="hero-spinner"></div>
           <span class="hero-canvas-status">Live Pure-Python Device</span>