[FE-11] Build StellarTransactionLink component

frontend/module/components/stellar-link/StellarTransactionLink.tsx

@@ -0,0 +1,53 @@
+"use client";
+
+import { useState } from "react";
+import { Copy, Check } from "lucide-react";
+
+interface StellarTransactionLinkProps {
+  txHash?: string | null;
+  network?: "testnet" | "mainnet";
+}
+
+export default function StellarTransactionLink({
+  txHash,
+  network = "testnet",
+}: StellarTransactionLinkProps) {
+  const [copied, setCopied] = useState(false);
+
+  if (!txHash) return null;
+
+  const url = `https://stellar.expert/explorer/${network}/tx/${txHash}`;
+  const truncated = `${txHash.slice(0, 8)}…${txHash.slice(-8)}`;
+
+  async function handleCopy() {
+    await navigator.clipboard.writeText(txHash);
+    setCopied(true);
+    setTimeout(() => setCopied(false), 2000);
+  }
+
+  return (
+    <span className="inline-flex items-center gap-1.5">
+      <a
+        href={url}
+        target="_blank"
+        rel="noopener noreferrer"
+        className="font-mono text-sm text-blue-600 underline hover:text-blue-800"
+      >
+        {truncated}
+      </a>
+      <button
+        type="button"
+        onClick={handleCopy}
+        aria-label={copied ? "Copied" : "Copy transaction hash"}
+        className="rounded p-0.5 text-gray-400 hover:text-gray-700 focus:outline-none focus:ring-2 focus:ring-blue-400"
+      >
+        {copied ? (
+          <Check className="h-3.5 w-3.5 text-green-500" aria-hidden="true" />
+        ) : (
+          <Copy className="h-3.5 w-3.5" aria-hidden="true" />
+        )}
+      </button>
+      {copied && <span className="text-xs text-green-600">Copied</span>}
+    </span>
+  );
+}