Harden runtime readiness

[heznpc]

Summary

• Add runtime/readiness docs for provider risk, release QA, and glossary status.
• Add a glossary status script and stricter file/script hygiene checks.
• Add logged-in live lesson shell fixture coverage and runtime privacy/fallback policy tests.
• Reduce duplicate translation provider calls by using content fallback only after background translation is unavailable.

Validation

• npm run glossary:status
• npm test
• npm run check:all
• npm run check:full

Notes

• AcademyLens remains unofficial and not affiliated with OpenAI.
• Google Translate remains the current fast runtime path, but CWS submission stays blocked until provider/privacy review is closed.