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/reusify/benchmarks/fib.js

@@ -0,0 +1,13 @@
+'use strict'
+
+function fib (num) {
+  var fib = []
+
+  fib[0] = 0
+  fib[1] = 1
+  for (var i = 2; i <= num; i++) {
+    fib[i] = fib[i - 2] + fib[i - 1]
+  }
+}
+
+module.exports = fib