ci(qualification): add reusable N-to-N+1 forward-upgrade flow

[SDAChess]

Description

Add a reusable N to N+1 forward-upgrade qualification flow. The flow installs the selected supported source release, establishes representative persisted state, upgrades through the target's documented package mechanism to the immutable candidate artifact set, and verifies the installation and state after the upgrade.

Rollback and downgrade to N-1 are explicitly outside this issue.

Context

• Parent release pipeline: feat: 0.1.0 release pipeline #2860
• Qualification composition contract: feat(ci): compose release qualification from targets, flows, and suites #2972
• Reusable release artifacts: chore(ci): clean up release pipeline #1683
• Shared driver conformance suite: spike: driver conformance suite for compute drivers #2183
• Release policy: RFC-0014

Forward upgrade is P0 across the initial release qualification matrix. The Fedora RPM and rootless Podman target is the first consumer, but source-version selection and upgrade sequencing must remain independent of the target and selected test suites.

Definition of Done

• The flow resolves and records the supported source release N and candidate N+1 artifact manifests.
• It verifies the source installation and version before creating test state.
• It creates representative persisted gateway state required by the supported upgrade contract.
• It upgrades using the target's documented package operation without rebuilding candidate artifacts.
• It verifies the candidate version, gateway health, required migrations, and preservation of supported state.
• It invokes independently selected post-upgrade suites, including creation and deletion of a new sandbox.
• It emits machine-readable step results and retains source-install, upgrade, migration, and target diagnostics on failure.
• It contains no Fedora-, Podman-, architecture-, or suite-specific implementation.
• Rollback and downgrade behavior are not implemented or implied.