Schedule enterprise audit-log exports for self-hosted operators #48

Summary

On-demand export exists (GET /api/v1/orgs/{id}/audit-logs/export). Roadmap v1.2 wants scheduled export. Self-hosted pilots still copy CSVs by hand.

Context

• tests/integration/test_audit_export.py
• src/voxforge/api/v1/orgs.py
• docs/ROADMAP.md

Scope

Start small: cron-friendly script + docs (org-scoped, existing CSV/JSON), not a SaaS email product.

Acceptance criteria

• scripts/audit_export_cron.sh (or equivalent) documented for VPS cron
• Uses existing export API + operator token/API key
• RBAC respected (cannot export another org)
• Integration or script test for payload shape
• No object-storage vendor required for v1