🧪 Add unit tests for sync-version.js

[cmuench]

🎯 What: The testing gap addressed
I added a unit test suite for the scripts/sync-version.js script, which was previously untested.

📊 Coverage: What scenarios are now tested

• Happy Path: Correctly updates manifest.json when its version is out of sync with package.json.
• No-op Path: Correctly identifies when versions are already in sync and skips the update.
• Edge Case: Handles various JSON formatting/spacing in manifest.json.
• Error Condition: Throws a descriptive error if manifest.json is missing the "version" field.

✨ Result: The improvement in test coverage
The scripts/sync-version.js script now has 100% logic coverage, ensuring that future changes to version synchronization or manifest structure won't break this critical part of the release process.

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PR created automatically by Jules for task 8121464447306251270 started by @cmuench

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