v0.4.1

Fixed — cross-host release reproducibility

• The release builder now pins Git archive timestamp handling to UTC and
  restores the caller's original TZ value, making all five generated release
  files byte-identical across supported host time zones for the same commit.
• The release-package smoke test now builds under conflicting Pacific and Asia
  time zones, fails if any archive or metadata file changes, and derives its
  expected release notes from the manifest-matched changelog section instead
  of stale version-specific text.
• Release metadata reads now request UTF-8 explicitly, preventing Windows
  PowerShell 5.1 from mangling non-ASCII changelog punctuation in release notes.