diigo-cache: a short page before the stated end peeks at the next page

The real fill failed at "diigo returned 44 items for page 167 of 168":
diigo's `total` overstates what load_user_items returns, so the true
last page looked short and the guard took it for a capped page size.

A short page that isn't the last by `total` now fetches the next page
(paced like any diigo call): empty means the data really ends there —
accepted, with a "total-overstated" notice logging total vs actual;
anything else means items would be skipped — refused, the message now
giving both counts. The fake gains an account whose total claims 60
more than it has; a fill on it runs to done.

Generated-by: Claude Opus 5.5

diigo-cache/tests/fill.test.ts

@@ -131,6 +131,14 @@ describe("fill job (goal 1e)", () => {
 		expect(status?.error).toMatch(/page size not honored/);
 	});
 
+	it("fills to the real end when diigo's total overstates its items", async () => {
+		const stub = await wired("fake-overstated-webapp");
+		await stub.startFill();
+		await drain(stub);
+		expect(await stub.fillStatus()).toMatchObject({ state: "done" });
+		expect((await stub.page(3, PAGE_SIZE)).items).toHaveLength(50);
+	});
+
 	it("a job saved under another page size fails instead of resuming; a new start replaces it", async () => {
 		const stub = await wired();
 		// the shape a 24-per-page job left in storage (no pageSize field)