feat: add copy dashboard URL button to header

src/components/DashboardHeader.tsx

@@ -1,4 +1,4 @@
-"use client"
+"use client";
 
 import { useEffect, useState } from "react";
 import { useSession } from "next-auth/react";
@@ -10,7 +10,10 @@ import KeyboardShortcuts from "@/components/KeyboardShortcuts";
 
 export default function DashboardHeader() {
   const { data: session } = useSession();
+
   const [isPublic, setIsPublic] = useState<boolean | null>(null);
+  const [copied, setCopied] = useState(false);
+  const [copyError, setCopyError] = useState(false);
 
   useEffect(() => {
     if (!session) {
@@ -21,6 +24,7 @@ export default function DashboardHeader() {
     async function loadSettings() {
       try {
         const res = await fetch("/api/user/settings");
+
         if (res.ok) {
           const data = await res.json();
           setIsPublic(data.is_public === true);
@@ -36,13 +40,32 @@ export default function DashboardHeader() {
     loadSettings();
   }, [session]);
 
+  const handleCopy = async () => {
+    try {
+      await navigator.clipboard.writeText(window.location.href);
+
+      setCopied(true);
+
+      setTimeout(() => {
+        setCopied(false);
+      }, 2000);
+    } catch {
+      setCopyError(true);
+
+      setTimeout(() => {
+        setCopyError(false);
+      }, 2000);
+    }
+  };
+
   return (
     <header className="mb-8 border-b border-[var(--border)] p-4 pb-6">
       <div className="flex flex-wrap items-center justify-between gap-3">
         <div>
           <h1 className="text-2xl md:text-3xl font-bold text-[var(--foreground)]">
             Dashboard
           </h1>
+
           <p className="mt-1 text-[var(--muted-foreground)]">
             Your coding activity at a glance
           </p>
@@ -60,8 +83,20 @@ export default function DashboardHeader() {
               Share Profile
             </a>
           )}
+
           <KeyboardShortcuts />
+
           <UserAvatar />
+
+          <button
+            type="button"
+            onClick={handleCopy}
+            aria-label="Copy dashboard link"
+            className="px-3 py-2 rounded-md border border-[var(--border)]"
+          >
+            {copied ? "✓ Copied!" : copyError ? "Failed" : "📋"}
+          </button>
+
           <ThemeToggle />
           <SignOutButton />
         </div>
@@ -70,4 +105,4 @@ export default function DashboardHeader() {
       <AccountToggle />
     </header>
   );
-}
+}