## Summary
- Add `Provider` entity for managing 3p deps from a sandbox
- Add provider CRUD API/server persistence and new CLI workflows (`nav provider create/get/list/update/delete`), including `--from-existing` laptop discovery.
- Integrate providers into sandbox create flow: infer from command (`-- claude`), support repeatable `--provider <type>`, prompt before auto-create, and allow manual in-sandbox setup.
- Add a dedicated `navigator-providers` crate with per-provider modules and mockable discovery test helpers.
## Key UX Changes
- `nav sandbox create --provider gitlab -- claude`
- Missing provider prompt now asks before creating from local state.
- `nav provider list --names` for scripting/cleanup.
## Test Plan
- `mise run cluster:deploy`
- `mise run test:e2e:sandbox`
- `mise run pre-commit`
Closes#19Closes#22Closes#11
Closes#13
## Summary
- add Python sandbox execution APIs for command and callable workflows
- consolidate sandbox policy fixtures and expand e2e test coverage for policy and Python exec paths
- update CI/build config and images for sandbox e2e execution dependencies
## Test Plan
- mise run pre-commit