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/16/solid/esm/ChatBubbleOvalLeftIcon.js

@@ -0,0 +1,24 @@
+import * as React from "react";
+function ChatBubbleOvalLeftIcon({
+  title,
+  titleId,
+  ...props
+}, svgRef) {
+  return /*#__PURE__*/React.createElement("svg", Object.assign({
+    xmlns: "http://www.w3.org/2000/svg",
+    viewBox: "0 0 16 16",
+    fill: "currentColor",
+    "aria-hidden": "true",
+    "data-slot": "icon",
+    ref: svgRef,
+    "aria-labelledby": titleId
+  }, props), title ? /*#__PURE__*/React.createElement("title", {
+    id: titleId
+  }, title) : null, /*#__PURE__*/React.createElement("path", {
+    fillRule: "evenodd",
+    d: "M1 8c0-3.43 3.262-6 7-6s7 2.57 7 6-3.262 6-7 6c-.423 0-.838-.032-1.241-.094-.9.574-1.941.948-3.06 1.06a.75.75 0 0 1-.713-1.14c.232-.378.395-.804.469-1.26C1.979 11.486 1 9.86 1 8Z",
+    clipRule: "evenodd"
+  }));
+}
+const ForwardRef = /*#__PURE__*/ React.forwardRef(ChatBubbleOvalLeftIcon);
+export default ForwardRef;