test: validate puzzle JSON schemas

[harshit3355]

Summary

• Validate every JSON file under samples/ and the puzzle definitions directory against the published KPuzzle or KPatternData schema.
• Add the validator to make test and the JavaScript CI job.
• Use the repository's existing cubing dependency and pin the temporary AJV CLI invocation.

Verification

• make test-json-schemas passed and validated 57 JSON files.
• Biome check passed for script/validate-json-schemas.ts.

[lgarron]

Thanks for the PR. Before I look at it, I need to ask if this follows the LLM policy: https://github.com/cubing/twips#llm-usage-policy