feat: add copy-to-clipboard button for code snippets

apps/web/src/app/dashboard/insights/page.tsx

@@ -1,5 +1,6 @@
 import { generateAiInsights } from "@/actions/insights";
 import ReactMarkdown from "react-markdown";
+import { PreBlock } from "@/components/copy-button";
 
 export const maxDuration = 30;
 
@@ -13,7 +14,15 @@ export default async function InsightsPage() {
       </div>
 
       <div className="bg-white p-8 rounded-2xl border border-gray-200 shadow-sm prose max-w-none text-gray-800">
-        <ReactMarkdown>{insights}</ReactMarkdown>
+        <ReactMarkdown
+          components={{
+            pre: ({ children, className }) => (
+              <PreBlock className={className}>{children}</PreBlock>
+            ),
+          }}
+        >
+          {insights}
+        </ReactMarkdown>
       </div>
     </div>
   );

apps/web/src/components/copy-button.tsx

@@ -0,0 +1,134 @@
+"use client";
+
+import { useState, useCallback, useRef, useEffect, type ReactNode } from "react";
+
+interface CopyButtonProps {
+  text: string;
+  className?: string;
+}
+
+export function CopyButton({ text, className = "" }: CopyButtonProps) {
+  const [copied, setCopied] = useState(false);
+  const timeoutRef = useRef<NodeJS.Timeout | null>(null);
+
+  useEffect(() => {
+    return () => {
+      if (timeoutRef.current) clearTimeout(timeoutRef.current);
+    };
+  }, []);
+
+  const handleCopy = useCallback(async () => {
+    try {
+      await navigator.clipboard.writeText(text);
+    } catch {
+      // Fallback for older browsers
+      const textarea = document.createElement("textarea");
+      textarea.value = text;
+      textarea.style.position = "fixed";
+      textarea.style.opacity = "0";
+      document.body.appendChild(textarea);
+      textarea.select();
+      document.execCommand("copy");
+      document.body.removeChild(textarea);
+    }
+    setCopied(true);
+    if (timeoutRef.current) clearTimeout(timeoutRef.current);
+    timeoutRef.current = setTimeout(() => setCopied(false), 2000);
+  }, [text]);
+
+  return (
+    <button
+      onClick={handleCopy}
+      className={`inline-flex items-center justify-center rounded-md p-1.5 text-gray-400 hover:text-gray-600 hover:bg-gray-100 transition-colors ${className}`}
+      title={copied ? "Copied!" : "Copy to clipboard"}
+      type="button"
+    >
+      {copied ? (
+        <svg
+          xmlns="http://www.w3.org/2000/svg"
+          width="16"
+          height="16"
+          viewBox="0 0 24 24"
+          fill="none"
+          stroke="currentColor"
+          strokeWidth="2"
+          strokeLinecap="round"
+          strokeLinejoin="round"
+          className="text-green-500"
+        >
+          <polyline points="20 6 9 17 4 12" />
+        </svg>
+      ) : (
+        <svg
+          xmlns="http://www.w3.org/2000/svg"
+          width="16"
+          height="16"
+          viewBox="0 0 24 24"
+          fill="none"
+          stroke="currentColor"
+          strokeWidth="2"
+          strokeLinecap="round"
+          strokeLinejoin="round"
+        >
+          <rect width="14" height="14" x="8" y="8" rx="2" ry="2" />
+          <path d="M4 16c-1.1 0-2-.9-2-2V4c0-1.1.9-2 2-2h10c1.1 0 2 .9 2 2" />
+        </svg>
+      )}
+    </button>
+  );
+}
+
+interface CodeBlockProps {
+  children: ReactNode;
+  className?: string;
+}
+
+export function CodeBlock({ children, className = "" }: CodeBlockProps) {
+  const codeRef = useRef<HTMLElement>(null);
+  const [codeText, setCodeText] = useState("");
+
+  useEffect(() => {
+    if (codeRef.current) {
+      setCodeText(codeRef.current.textContent || "");
+    }
+  }, [children]);
+
+  return (
+    <div className="relative group">
+      <div className="absolute top-2 right-2 opacity-0 group-hover:opacity-100 transition-opacity z-10">
+        <CopyButton text={codeText} />
+      </div>
+      <code ref={codeRef} className={className}>
+        {children}
+      </code>
+    </div>
+  );
+}
+
+interface PreBlockProps {
+  children: ReactNode;
+  className?: string;
+}
+
+export function PreBlock({ children, className = "" }: PreBlockProps) {
+  const preRef = useRef<HTMLPreElement>(null);
+  const [codeText, setCodeText] = useState("");
+
+  useEffect(() => {
+    if (preRef.current) {
+      const codeEl = preRef.current.querySelector("code");
+      setCodeText((codeEl || preRef.current).textContent || "");
+    }
+  }, [children]);
+
+  return (
+    <div className="relative group">
+      <div className="absolute top-2 right-2 opacity-0 group-hover:opacity-100 transition-opacity z-10">
+        <CopyButton text={codeText} />
+      </div>
+      <pre ref={preRef} className={className}>
+        {children}
+      </pre>
+    </div>
+  );
+}