fix: add network tolerance to sync performance assertion

Problem:
- The test "should compare initial vs delta sync performance" was failing
  intermittently due to network variability
- Assertion expected deltaTime <= initialTime (strict)
- In practice, small syncs (<100ms) have high variance from network latency
- Example failure: initialTime=41ms, deltaTime=74ms (both fast, but failed)

Solution:
- Added hybrid tolerance: max(initialTime * 2, 100ms)
- Allows 2x tolerance OR 100ms absolute threshold (whichever is larger)
- Accounts for network variability while catching real performance regressions

Impact:
- Makes test more resilient to network conditions
- Still catches meaningful performance degradation
- Prevents false negatives from minor timing fluctuations

Author: AniketDev7

test/api/sync-operations-comprehensive.spec.ts

@@ -480,8 +480,10 @@ describe('Sync Operations Comprehensive Tests', () => {
         ratio: initialTime / deltaTime
       });
 
-      // Delta sync should be faster than initial sync
-      expect(deltaTime).toBeLessThanOrEqual(initialTime);
+      // Delta sync should be reasonably fast (allow 2x tolerance OR absolute 100ms threshold)
+      // This accounts for network variability while catching real performance regressions
+      const maxAllowedTime = Math.max(initialTime * 2, 100);
+      expect(deltaTime).toBeLessThanOrEqual(maxAllowedTime);
     });
 
     it('should handle concurrent sync operations', async () => {