fix(news): persist publication requests and retry cache delivery

src/lib/article-request.ts

@@ -0,0 +1,45 @@
+export interface ArticleRequest {
+	signature: string;
+	key: string;
+}
+/** Retain only a fingerprint and request ID, never editorial content. */
+export async function articleRequest(
+	form: FormData,
+	scope: string,
+	previous?: ArticleRequest,
+	storage?: Pick<Storage, "getItem" | "setItem">,
+): Promise<ArticleRequest> {
+	const entries = [...form.entries()]
+		.filter(([key]) => key !== "requestKey")
+		.sort(([a], [b]) => a.localeCompare(b));
+	const digest = await crypto.subtle.digest(
+		"SHA-256",
+		new TextEncoder().encode(JSON.stringify([scope, entries])),
+	);
+	const signature = Array.from(new Uint8Array(digest), (byte) =>
+		byte.toString(16).padStart(2, "0"),
+	).join("");
+	const storageKey = `cms:news:request:${scope}`;
+	let saved = previous;
+	if (!saved) {
+		try {
+			saved = JSON.parse(storage?.getItem(storageKey) ?? "null") ?? undefined;
+		} catch {
+			/* Storage may be disabled. */
+		}
+	}
+	if (
+		saved?.signature === signature &&
+		/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/i.test(
+			saved.key,
+		)
+	)
+		return saved;
+	const next = { signature, key: crypto.randomUUID() };
+	try {
+		storage?.setItem(storageKey, JSON.stringify(next));
+	} catch {
+		/* The editor retains the key in memory. */
+	}
+	return next;
+}