Prepare graph-tool-call 0.42.0 release

[SonAIengine]

Summary

• bump package and public evidence surfaces to 0.42.0
• publish reproducible 1,000-tool Arazzo 3/10/30-call evaluation evidence
• document large OpenAPI ingest hardening and refresh release artifacts

Validation

• make quick (266 passed, 3 skipped)
• make release-check (1240 passed, 47 skipped)
• release evidence freshness checks
• wheel/sdist metadata checks and clean public wheel smoke
• Arazzo long-horizon benchmark: 3/10/30-call cases all pass goal, order, and binding gates

This PR is ready for review and is not a draft.