Add movie fusion packages with locked media, ZIP export, and batch forge UI.

Paired video mode encrypts movies, uses runner-only lock hints, bundles README plus artifacts per title, and supports batch forging with progress.

server/web/src/components/DownloadButton.tsx

@@ -0,0 +1,33 @@
+import { useState, type ReactNode } from 'react';
+import { downloadApiFile } from '../api/download';
+
+type Props = {
+  apiPath: string;
+  filename: string;
+  className?: string;
+  children: ReactNode;
+};
+
+/** Click to save an API file to the browser Downloads folder. */
+export default function DownloadButton({ apiPath, filename, className, children }: Props) {
+  const [busy, setBusy] = useState(false);
+
+  const handleClick = async (e: React.MouseEvent) => {
+    e.preventDefault();
+    if (busy) return;
+    setBusy(true);
+    try {
+      await downloadApiFile(apiPath, filename);
+    } catch (err) {
+      window.alert(err instanceof Error ? err.message : 'Download failed');
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <button type="button" className={className} onClick={handleClick} disabled={busy}>
+      {busy ? 'Downloading…' : children}
+    </button>
+  );
+}