Summary

• replace manual cold-session transcript replay loops with engine.apply_transcript in node-basic and nextjs-basic examples
• simplify example 06 by using engine.apply_transcript directly for replay onto current engine state
• preserve existing filtering and response behavior

Why

This makes replay intent clearer in request-scoped examples and aligns examples with the newly restored API parity surface.

Scope checklist

• Diff is minimal and scoped to the requested behavior
• Python/spec parity is preserved (or mismatch is explicitly documented)
• Fixture semantics are respected (exact string vs non-empty null rule)
• No unrelated refactors
• Relevant tests were run

Notes

• Validation run: npm test (all passing).
• No engine behavior changes.
• No fixture or CI workflow changes.