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/fast-glob/out/utils/string.js

@@ -0,0 +1,11 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.isEmpty = exports.isString = void 0;
+function isString(input) {
+    return typeof input === 'string';
+}
+exports.isString = isString;
+function isEmpty(input) {
+    return input === '';
+}
+exports.isEmpty = isEmpty;