`test: schema.test.ts` combines multiple responsibilities into a single test file

[SHUBHANSHU602]

schema.test.ts validates a wide range of unrelated behaviors:

schema type inference
constraint humanization
JSON → schema conversion
dependency resolution
server variable conversion
snapshot-based rendering output

This mirrors a deeper issue where SchemaHelpers behaves as a God utility, and the test file reflects that same lack of separation.

Problems caused:

Tests are hard to reason about
Refactoring any one concern risks breaking many unrelated tests
Extending functionality becomes risky and error-prone

[AceTheCreator]

Please don't open issues that re not necessary for the sake of GSoC, please refrain from doing that.