Drop the paper-coloured backing rect so the favicon is fully transparent
and adapts to the tab/surface behind it.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011SDkz6ft4rhf4WekytP8jc

diff --git a/public/favicon.svg b/public/favicon.svg
index f927618..d065896 100644
--- a/public/favicon.svg
+++ b/public/favicon.svg
@@ -1,5 +1,4 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true">
-  <rect width="24" height="24" rx="5" fill="#f3efe6"/>
   <g fill="none" stroke-width="1.7" stroke-linecap="round" stroke-linejoin="round">
     <path stroke="#2a261f" d="M5 21 V9 L12 3.5 L19 9 V21 Z"/>
     <line stroke="#9a5a3c" x1="8.5" y1="12.5" x2="15.5" y2="12.5"/>