Phase 1 slice 3c: Route bulk sandbox cleanup through the OpenShell lifecycle adapter

Parent: #9811

## Product decision

- Decision: Accept
- Reason: Close the accepted production sandbox lifecycle boundary after named deletion and semantic creation have migrated.
- Placement: Extend the OpenShell lifecycle adapter under `src/lib/adapters/openshell/` and update the existing uninstall owner without moving uninstall authorization or cleanup ordering into the adapter.
- Accountable maintainer and implementation owner: @rsliter
- Validation plan: Exact CLI adapter tests, uninstall typed-fake tests, current full-uninstall regression suites, repository boundary inventory, and focused existing E2E only where selected-gateway ownership cannot be covered locally.
- Approval: Inherits the accepted decision recorded on #9811 on 2026-09-15.

## Outcome

Route the accepted unscoped full-uninstall sandbox cleanup through the typed lifecycle boundary and close the production create/delete command inventory.

## Scope

- Preserve `sandbox delete --all` only when full uninstall owns the selected gateway.
- Treat zero exit as accepted and require authoritative cleanup evidence before deleting provider, gateway, or registry state.
- Preserve all owned state when deletion is partial, ambiguous, or unverifiable.
- Remove obsolete production create/delete execution paths after the named-delete and semantic-create slices merge.
- Record remaining plugin, tooling, E2E, and provider-specific occurrences under their accepted owners.

## Exclusions

- Named single-sandbox deletion, owned by the first #9811 slice.
- Semantic sandbox creation, owned by the second #9811 slice.
- Plugin lifecycle migration: #9813.
- SDK and gRPC implementations: #9826.
- New uninstall behavior, retry policy, or gateway ownership rules.