Define 1.0 beta release-candidate smoke matrix

## Goal Create a concrete go/no-go smoke matrix for a 1.0 beta release candidate so beta readiness is not judged only by build/test status. ## Context The automated checks already cover Swift tests, release-note composition, bundle validation, and appcast validation. Before a 1.0 beta, Contained also needs a manual product smoke pass that exercises the default sidebar app, major workflows, degraded states, and experimental gates in a real app bundle. ## Smoke areas - First launch and onboarding/bootstrap states. - Missing CLI, located CLI, unsupported CLI, stopped service, and ready service. - Container create, run, stop, restart, edit/recreate, delete, inspect, logs, terminal, stats, history, and files. - Image pull, local image selection, update checks, load archive, save/archive, tag, push, prune, and build workspace when enabled. - Compose import from file, paste, and drag/drop when enabled. - Volume and network create, inspect, delete, prune, grouping, and filters. - Registry login/logout and password handling. - System page service lifecycle, disk usage, runtime settings, logs, and storage cleanup. - Settings tabs, backup/export, import, downgrade guard, release notes, and update channels. - Menu bar extra, app menu commands, keyboard shortcuts, command palette, and toolbar-first experimental UI. - Empty, loading, error, context-menu, drag/drop, and multi-selection states where supported. ## Implementation checklist - [ ] Turn the smoke areas above into a reusabl...