Fix flaky TTL cache test timing

Use a 20ms TTL with a 40ms wait so the expiry window is long enough
for the immediate second read to hit the in-memory cache reliably.

src/lib/cache.test.ts

@@ -36,10 +36,11 @@ describe("cached (memory-only, no Redis)", () => {
 		let count = 0;
 		const fn = vi.fn(async () => ++count);
 		const key = `ttl-${Math.random()}`;
-		expect(await cached(key, 1, fn)).toBe(1);
-		expect(await cached(key, 1, fn)).toBe(1);
-		await new Promise((r) => setTimeout(r, 10));
-		expect(await cached(key, 1, fn)).toBe(2);
+		const ttl = 20;
+		expect(await cached(key, ttl, fn)).toBe(1);
+		expect(await cached(key, ttl, fn)).toBe(1);
+		await new Promise((r) => setTimeout(r, 40));
+		expect(await cached(key, ttl, fn)).toBe(2);
 		expect(fn).toHaveBeenCalledTimes(2);
 	});