feat: add full Deno sandbox permissions and derive env from secrets
- Add run, ffi, sys, hrtime permission types to match all Deno sandbox options
- Derive --allow-env from configured secrets instead of manifest declarations
- Update VOD bundle to use valibot schemas for input validation
- Add ROADMAP.md documenting future ideas beyond the PoC
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>