refactor(game): rework team allocation and add GamePrepareEvent hook

[theEvilReaper]

Proposed changes

Adds the GamePrepareEvent as a trigger for stamina initialization and uses that as an opportunity to split TeamHelper.prepareTeamAllocation into clearly separated steps (selection, tagging, assignment).

The survivor set is now returned explicitly as a TeamAllocation instead of being re-fetched from the team object later on.

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

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• I have read the CONTRIBUTING.md
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[github-actions]

Test results

 96 files   96 suites   50s ⏱️
 93 tests  88 ✅  5 💤 0 ❌
282 runs  267 ✅ 15 💤 0 ❌

Results for commit e429123.

♻️ This comment has been updated with latest results.