test(conformance): add sandbox lifecycle scenario

[elezar]

Summary

Add portable lifecycle conformance coverage and make Fedora CI validate the built candidate RPMs directly rather than upgrading from a released baseline.

Related Issue

No issue required: localized conformance coverage and CI-test-flow extension requested directly.

Changes

• Refactor conformance scenarios into a common execution trait with composable collections.
• Add the public sandbox-lifecycle collection with private stop/start and stopped-deletion leaves.
• Run the built candidate RPMs through the restart-only conformance plan before the plan-driven continuity check.
• Retain the upgrade plan and action contract for dedicated upgrade testing.

Testing

• mise run pre-commit passes
• Unit tests added/updated
• E2E tests added/updated (scenario coverage added; target-backed execution is running in CI)
• cargo test -p openshell-conformance -p openshell-conformance-cli
• cargo clippy -p openshell-conformance -p openshell-conformance-cli --all-targets -- -D warnings

Checklist

• Follows Conventional Commits
• Commits are signed off (DCO)
• Architecture docs updated (if applicable)

[copy-pr-bot]

Auto-sync is disabled for draft pull requests in this repository. Workflows must be run manually.

Contributors can view more details about this message here.