ui: unify logo across themes and update favicon

static/readme-logo-dark.svg

@@ -1,19 +1,19 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" width="100" height="100">
   <defs>
-    <radialGradient id="bg-dark" cx="35%" cy="35%" r="75%">
+    <radialGradient id="bg" cx="35%" cy="35%" r="75%">
       <stop offset="0%" stop-color="#FB923C" />
       <stop offset="100%" stop-color="#C2410C" />
     </radialGradient>
-    <clipPath id="clip-dark">
+    <clipPath id="clip">
       <circle cx="50" cy="50" r="45" />
     </clipPath>
   </defs>
 
   <!-- Base -->
-  <circle cx="50" cy="50" r="45" fill="url(#bg-dark)" />
+  <circle cx="50" cy="50" r="45" fill="url(#bg)" />
 
   <!-- Crescent moon cutout -->
-  <g clip-path="url(#clip-dark)">
+  <g clip-path="url(#clip)">
     <path
       d="M70 50a25 25 0 1 1 -25 -25 20 20 0 1 0 25 25z"
       fill="#FFF7ED"