🧪 [Testing] Add unit tests for parseArgs in generate-manifest.js

[akutuva21]

🎯 What: Added unit test coverage for the parseArgs function in scripts/generate-manifest.js.
📊 Coverage: Added tests covering default behavior, root, output flag parsing, combination of flags, and edge cases.
✨ Result: Improved test coverage and reliability for argument parsing during manifest generation.

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PR created automatically by Jules for task 14940311204121168699 started by @akutuva21

[google-labs-jules]

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[akutuva21]

pull the latest code and resolve merge conflicts

[google-labs-jules]

pull the latest code and resolve merge conflicts

I have pulled the latest code, resolved the merge conflicts in scripts/generate-manifest.test.js, and verified that all tests are passing.