🧪 Add test for invalid JSON load error path

[sneakocom]

🎯 What: The testing gap addressed (untested invalid JSON load error path)
📊 Coverage: Test coverage for when load_json encounters a non-object JSON file
✨ Result: Improved test coverage by verifying the ValueError when loading invalid top-level JSON values.

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PR created automatically by Jules for task 4593427041332253505 started by @sneakocom

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