[constants] Refactor 1000 to MS_PER_SECOND

- Extracted MS_PER_SECOND to src/constants.mjs
- Replaced literal 1000 in src/relay-health.mjs, src/utils.mjs, src/lib.mjs, src/lock-ops.mjs
- Updated test/scheduler-lock-failure-schema.contract.test.mjs to copy constants.mjs
- Added task log and artifacts

Co-authored-by: PR0M3TH3AN <[email protected]>

src/test_logs/TEST_LOG_2026-02-19T21-26-08Z.md

@@ -0,0 +1,8 @@
+- Command: npm run lint
+- Result: Passed
+
+- Command: npm run validate:scheduler-failure-schema
+- Result: Passed
+
+- Command: npm test
+- Result: Passed