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/autoprefixer/lib/hacks/pixelated.js

@@ -0,0 +1,34 @@
+let OldValue = require('../old-value')
+let Value = require('../value')
+
+class Pixelated extends Value {
+  /**
+   * Different name for WebKit and Firefox
+   */
+  old(prefix) {
+    if (prefix === '-webkit-') {
+      return new OldValue(this.name, '-webkit-optimize-contrast')
+    }
+    if (prefix === '-moz-') {
+      return new OldValue(this.name, '-moz-crisp-edges')
+    }
+    return super.old(prefix)
+  }
+
+  /**
+   * Use non-standard name for WebKit and Firefox
+   */
+  replace(string, prefix) {
+    if (prefix === '-webkit-') {
+      return string.replace(this.regexp(), '$1-webkit-optimize-contrast')
+    }
+    if (prefix === '-moz-') {
+      return string.replace(this.regexp(), '$1-moz-crisp-edges')
+    }
+    return super.replace(string, prefix)
+  }
+}
+
+Pixelated.names = ['pixelated']
+
+module.exports = Pixelated