chore(json): Typing improvements

[ibgreen-openai]

Summary

This PR cleans up the JSON module API to make JSONConfiguration simpler and more type-safe, updates internal callers to the new shape, and expands tests/docs to cover the new behavior.

Compared to master, this PR:

• simplifies JSONConfiguration around a single plain-object API
• makes JSON configuration hooks explicit and typed
• removes legacy/deprecated configuration patterns from internal usage
• updates JSON tests and docs to match the new API
• fixes a brittle data-filter test assertion that was failing in full-suite runs

What Changed

JSON API cleanup

• Refactored JSONConfiguration to accept one typed config object instead of mixed or variadic forms.
• Added explicit typed support for runtime hooks:
  • convertFunction
  • preProcessClassProps
  • postProcessConvertedJson
• Kept data config under the config bag while preserving hook behavior across merges/cloning.
• Made merge() operate on the same plain-object config shape as the constructor.
• Updated JSONConverter.mergeConfiguration() to accept plain config objects again.

Internal call sites

• Updated in-repo callers to the new configuration shape.
• Removed remaining internal reliance on deprecated constructor patterns.
• Kept Jupyter playground JSON configuration merging working with plain objects.

Tests

• Added regression coverage for:
  • plain-object JSONConfiguration construction and merging
  • JSONConverter.mergeConfiguration() with plain objects
  • hook preservation across merges/clones
  • hook execution during conversion
  • JSONLayer configuration override behavior
• Resolved merge-conflict fallout in JSON tests.
• Fixed a brittle assertion in test/modules/extensions/data-filter.spec.ts to validate only initialized attribute values.

Docs

• Updated JSON API docs to describe the cleaned-up single-object configuration model.
• Updated docs/examples to use classes and the supported hook fields.
• Added TSDoc across the JSON runtime surface for exported types, classes, functions, props, and fields.

Notes

This intentionally favors a cleaner internal/API model over backward compatibility for older external JSON configuration patterns. The in-repo behavior is preserved and now covered by tests.

Validation

yarn build
yarn test
yarn lint

[coveralls]

coverage: 80.359% (+0.02%) from 80.339%
when pulling 1dfb76f on ib/json-cleanup
into 8a019c8 on master.

[chrisgervang]

Nice cleanups and typings. Left a small comment/question.

What is the perf increase coming from? By removing validate? Edit: I misread "prep" for "perf"

[chrisgervang]

Is the switch necessary?