fix(tests,ci): recency floating-point precision and checkout action version

Author: ZeR020

.github/workflows/periodic-review.yml

@@ -13,7 +13,7 @@ jobs:
   review-trigger:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0  # Full history for counting
 

tests/memory-scoring.test.ts

@@ -15,7 +15,7 @@ describe("memory-scoring", () => {
   describe("calculateRecency", () => {
     it("returns 1.0 for very recent memories", () => {
       const now = Date.now();
-      expect(calculateRecency(now, 7)).toBe(1.0);
+      expect(calculateRecency(now, 7)).toBeCloseTo(1.0, 10);
     });
 
     it("returns lower values for older memories", () => {