test: hardened two ci-flaky timing tests

- mnemopi provider parity 'diagnose, validate, graph' does ~6.7s of real
  work under bun --parallel=8 on loaded runners; raised its per-test
  timeout to 30s (default 5s flaked twice in three CI runs).
- utils LRUCache updateAgeOnGet drove a 30ms TTL with real 20ms sleeps
  (10ms margin); now drives performance.now() via a mocked clock, so the
  contract is asserted deterministically with no wall-clock wait.

packages/mnemopi/test/provider-all-15-tools-parity.test.ts

@@ -172,5 +172,5 @@ describe("provider all-tools parity", () => {
 		});
 		expect(shared.status).toBe("stored_shared");
 		expect((await handleToolCall("mnemopi_shared_forget", { memory_id: shared.memory_id })).status).toBe("deleted");
-	});
+	}, 30_000);
 });

packages/utils/test/lru.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, test } from "bun:test";
+import { describe, expect, test, vi } from "bun:test";
 import { LRUCache } from "../src/lru";
 
 describe("LRUCache", () => {
@@ -86,15 +86,22 @@ describe("LRUCache", () => {
 		});
 	});
 
-	test("matches updateAgeOnGet", async () => {
-		const cache = new LRUCache<string, number>({ max: 2, ttl: 30, updateAgeOnGet: true });
-		cache.set("a", 1);
-		// Integration against the cache's performance-based clock requires real elapsed time.
-		await Bun.sleep(20);
-		expect(cache.get("a")).toBe(1);
-		await Bun.sleep(20);
-		expect(cache.has("a")).toBe(true);
-		await Bun.sleep(20);
-		expect(cache.has("a")).toBe(false);
+	test("matches updateAgeOnGet", () => {
+		// Drive the cache's performance.now() clock deterministically — the real
+		// clock version (30ms TTL, 20ms sleeps) raced CI load and flaked.
+		let now = 0;
+		const clock = vi.spyOn(performance, "now").mockImplementation(() => now);
+		try {
+			const cache = new LRUCache<string, number>({ max: 2, ttl: 30, updateAgeOnGet: true });
+			cache.set("a", 1);
+			now = 20;
+			expect(cache.get("a")).toBe(1); // refreshes the entry's age to t=20
+			now = 40;
+			expect(cache.has("a")).toBe(true); // 20ms since refresh < 30ms TTL
+			now = 60;
+			expect(cache.has("a")).toBe(false); // 40ms since refresh > 30ms TTL
+		} finally {
+			clock.mockRestore();
+		}
 	});
 });