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/fraction.js/examples/tape-measure.js

@@ -0,0 +1,16 @@
+/*
+Fraction.js v5.0.0 10/1/2024
+https://raw.org/article/rational-numbers-in-javascript/
+
+Copyright (c) 2024, Robert Eisele (https://raw.org/)
+Licensed under the MIT license.
+*/
+const Fraction = require('fraction.js');
+
+function closestTapeMeasure(frac) {
+
+    // A tape measure is usually divided in parts of 1/16
+
+    return Fraction(frac).roundTo("1/16");
+}
+console.log(closestTapeMeasure("1/3")); // 5/16