Summary

Adjusts the in-game update checker to work on clean release artifacts even when GitTag is empty, while keeping safeguards for dirty builds.

What changed

• Accept clean builds with either:
  • non-empty GitTag, or
  • valid GitCommitTimeStamp.
• Keep blocking update checks for dirty builds (GitUncommittedChanges).
• Use published_at vs local GitCommitTimeStamp when available.
• Fall back to tag comparison only when a local GitTag exists.
• Update header comments to reflect the new release eligibility rule.

Validation

• Compared with functional branch state (hotfix/update-checker-beta-5) for:
  • Core/GameEngine/Source/Common/UpdateChecker.cpp
  • Core/GameEngine/Include/Common/UpdateChecker.h
• Local runtime behavior confirmed as functional.

Scope

• Update-checker behavior only.
• No gameplay logic changes.