feat: copy agent prompt to clipboard instead of generating a file in ui.html

ui.html

@@ -317,9 +317,7 @@
           
           zip.file("data.md", msg.markdown);
           
-          const agentMarkdown = `# SYSTEM PROMPT: FIGMA-TO-CODE FRONTEND ENGINEERING AGENT
-
-You are a precise Frontend Engineering Agent. Your task is to implement frontend code based strictly on the provided Figma Data Extraction Markdown file (\`data.md\`) and its accompanying exported assets.
+          const agentMarkdown = `You are a precise Frontend Engineering Agent. Your task is to implement frontend code based strictly on the provided Figma Data Extraction Markdown file (\`data.md\`) and its accompanying exported assets.
 
 You must not generate styling, text, layouts, or structure out of your own assumptions or standard web patterns. Everything must be mapped directly from the source design data.
 
@@ -359,7 +357,12 @@ You are strictly forbidden from guessing, approximating, or auto-generating valu
 3. **Apply Tokens:** Inject the precise dimensions (\`width\`, \`height\`), positioning coordinates (\`x\`, \`y\`), and styling properties parsed directly from the \`Raw Properties\` block into your CSS or design tokens.
 4. **Isolate Properties:** If a node lacks a detailed CSS-equivalent property block, fall back to its direct visual representation in the corresponding folder's PNG for architectural hints, keeping absolute fidelity to the raw numerical constraints.`;
 
-          zip.file("agent.md", agentMarkdown);
+          const textArea = document.createElement("textarea");
+          textArea.value = agentMarkdown;
+          document.body.appendChild(textArea);
+          textArea.select();
+          document.execCommand("copy");
+          textArea.remove();
           
           for (const img of msg.images) {
             const filePath = img.folder ? `${img.folder}/${img.name}` : img.name;