docs(design): remove SVG, use PNG logo only

SVG icon is no longer in use. public/logo.png (1024x1024 RGBA) is
the single logo asset. DESIGN.md updated accordingly: SVG snippet
removed, wordmark pattern and <head> references updated to PNG.

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

node_modules/@heroicons/react/index.esm.js

@@ -0,0 +1,16 @@
+// The only reason this file exists is to appease Vite's optimizeDeps feature which requires a root-level import.
+
+export default new Proxy(
+  {},
+  {
+    get: (_, property) => {
+      if (property === '__esModule') {
+        return {}
+      }
+
+      throw new Error(
+        `Importing from \`@heroicons/react\` directly is not supported. Please import from either \`@heroicons/react/16/solid\`, \`@heroicons/react/20/solid\`, \`@heroicons/react/24/solid\`, or \`@heroicons/react/24/outline\` instead.`
+      )
+    },
+  }
+)