fix([issue-6994]): extend server close grace period for TLS teardown

[atomantic]

Closes #6994

Summary

• Extend the default closeServer grace window from 250ms to 1000ms so TLS/socket teardown can complete without routine false error warnings.
• Keep the shutdown path bounded and preserve the existing late-callback/error handling behavior.

Verification

• npm test --prefix server -- services/bootstrap.shutdown.test.js
• 6 tests passed

Review

• Local code review completed cleanly.
• Requested Claude review was run with medium effort; its output was malformed for the strict verdict format, so it is recorded as an optional no-verdict pass.