fix: revert font loading to CDN (clean state)

Local font approach broke HF pushes (binary files rejected).
CDN has CORS * confirmed — fonts load cross-origin fine.
Correct Anthropic Mono URL (69971a2e...) in place.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -12,3 +12,5 @@ dist/
 build/
 *.egg-info/
 .DS_Store
+.vercel
+ui/public/fonts/

ui/src/index.css

@@ -10,21 +10,21 @@
    ════════════════════════════════════════════════════════════════════════ */
 @font-face {
   font-family: "Anthropic Sans";
-  src: url(/fonts/69971a00a3295036497e1a28_AnthropicSans-Roman-Web.woff2) format("woff2");
+  src: url(https://cdn.prod.website-files.com/67ce28cfec624e2b733f8a52/69971a00a3295036497e1a28_AnthropicSans-Roman-Web.woff2) format("woff2");
   font-weight: 300 800;
   font-style: normal;
   font-display: swap;
 }
 @font-face {
   font-family: "Anthropic Sans";
-  src: url(/fonts/69971a016067bf14b9b8f48d_AnthropicSans-Italic-Web.woff2) format("woff2");
+  src: url(https://cdn.prod.website-files.com/67ce28cfec624e2b733f8a52/69971a016067bf14b9b8f48d_AnthropicSans-Italic-Web.woff2) format("woff2");
   font-weight: 300 800;
   font-style: italic;
   font-display: swap;
 }
 @font-face {
   font-family: "Anthropic Mono";
-  src: url(/fonts/69971a2e55d24d61bc045b1a_AnthropicMono-Roman-Web.woff2) format("woff2");
+  src: url(https://cdn.prod.website-files.com/67ce28cfec624e2b733f8a52/69971a2e55d24d61bc045b1a_AnthropicMono-Roman-Web.woff2) format("woff2");
   font-weight: 300 800;
   font-style: normal;
   font-display: swap;