feat(world-lab): save exports to sqlite

[christopherjnelson]

Summary

• add manual Save to SQLite for the current generated experiment export
• archive the exact validated artifact through a narrow Game API endpoint
• reuse the transactional, idempotent local archive importer without automatic persistence or browser-selected paths
• add safe error handling, duplicate-request protection, focused coverage, and architecture/security documentation

Validation

Repository owner confirmed the complete local suite is green:

• pnpm format:check
• pnpm lint
• pnpm typecheck
• pnpm test
• pnpm build
• pnpm test:e2e