[woksin]

Changed

• Split the in-process event sequence, projection capability checks and projection value conversion in the testing package into smaller focused modules, with no change to public APIs, error messages or behavior (Code Health: raise the in-process testing support to 9.5 #289)

[woksin]

Notes for reviewers:

• Behavior-preserving refactor. 27 characterization specs were added before each refactor to pin error messages, validation and rejection order, cloning/defaults, append failure latching, seed rollback and subject fallback.
• Code Health: ProjectionCapabilities 2.85 -> 10, ProjectionValueConverter 5.52 -> 10, InProcessEventSequence 3.44 -> 9.09; every new helper module scores 10 (two interface-only modules have no score). The remaining InProcessEventSequence findings concern its public method signatures and are left for the next major.
• Local checks: yarn install --immutable, yarn ci (builds, typechecks, ESM smoke test, 3931 specs passed, 1 skipped) and yarn test in Source. Integration tests against a kernel run in CI only.
• Independent cross-provider review of the whole change: passed, no blocking findings.