refactor: rename diigo-dump to diigo-cache

Pure rename ahead of the dump worker's evolution into a bookmark cache
(goal 1c), so history follows the files. The diigo-login helper script
is dropped: the cookie now enters through webapp's mint form, never a
local script.

diigo-cache/src/diigo.ts

@@ -0,0 +1,48 @@
+/**
+ * @file Diigo dump logic: the bookmark generator over any fluent handle.
+ * Site-flavored configuration (URL, headers, cookie) lives where the webapp
+ * instance is minted (src/index.ts: mint); only the traversal is here.
+ */
+
+export type PagedGet = {
+	pathjoin(ref: string): PagedGet;
+	query(params: Record<string, string | number>): PagedGet;
+	get(): Promise<string>;
+};
+
+export type DumpOptions = {
+	/** fluent handle for the diigo account, cookie attached upstream */
+	diigoAPI: PagedGet;
+	pages?: number;
+	count?: number;
+	log?: (event: Record<string, unknown>) => void;
+};
+
+/** yield diigo bookmarks, most-recently-updated first, `pages * count` at
+ * most. `diigoAPI` is attenuated authority; over RPC the generator runs in
+ * the caller's address space against a stub. */
+export async function* dumpBookmarks({
+	diigoAPI,
+	pages = 2,
+	count = 24,
+	log = () => {},
+}: DumpOptions): AsyncGenerator<Record<string, unknown>> {
+	const getUserItems = (page: number) =>
+		diigoAPI
+			.pathjoin("load_user_items")
+			.query({ sort: "updated", count, page_num: page })
+			.get()
+			.then(JSON.parse) as Promise<{ total: number; items: Record<string, unknown>[] }>;
+
+	const first = await getUserItems(1);
+	const totalPages = Math.ceil(first.total / count);
+	log({ event: "start", total: first.total, pages, totalPages });
+
+	let got = 0;
+	for (let page = 1; page <= Math.min(pages, totalPages); page += 1) {
+		const data = page === 1 ? first : await getUserItems(page);
+		yield* data.items;
+		got += data.items.length;
+		log({ event: "page", page, of: pages, got });
+	}
+}