fix: use Roboto Serif from Google Fonts

Author: nikhilwoodruff

docs/src/app/globals.css

@@ -1,4 +1,4 @@
-@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&family=Instrument+Serif:ital@0;1&display=swap');
+@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&family=Roboto+Serif:wght@400;500;600;700&display=swap');
 @import "tailwindcss";
 
 @theme {
@@ -103,7 +103,7 @@ code {
 
 /* Agent response content */
 .response-content {
-  font-family: Georgia, "Times New Roman", Times, serif;
+  font-family: "Roboto Serif", Georgia, serif;
   font-size: 16px;
   line-height: 1.7;
   color: #1e293b;