chore: public OSS release 2.9.2

[keshprad]

Summary

Publishes the public OSS snapshot for SkillSpector 2.9.2.

• Adds bounded retries with backoff for malformed structured LLM responses.
• Retains fail-closed isolation once the retry budget is exhausted.
• Updates the version, lockfile, changelog, release note, and targeted regression coverage.

Validation

• make test-unit in the sanitized OSS snapshot: 1936 passed, 13 skipped, 38 deselected, 4 xfailed.
• git diff --check: passed.
• Public-only workflows, templates, and policy files were preserved.

Release scope

This is an OSS release snapshot derived from internal commit fcf4fa1.