Refine app operator UX

[kacy]

Summary

This refines the app-first operator surface so rollback, status, apps, and history behave consistently across local and remote usage.

What Changed

• made yoq rollback --app perform a real rollback apply locally instead of only printing the stored snapshot
• added --print for non-mutating local and remote rollback snapshot inspection
• defaulted app rollback target selection to the previous successful release when --release is omitted
• added canonical nested JSON views for app status and history (current_release, previous_successful_release, workloads, training_runtime / release)
• added yoq apps rollout filters: --status, --failed, and --in-progress
• tightened app history/status text output with clearer release markers and rollout summaries
• updated operator docs and shell completion/help text to match the new app-first behavior

Why

The app control plane was already unified underneath, but the operator UX still had one major asymmetry: local app rollback printed config while remote rollback re-applied releases. Status, apps, and history also relied too much on top-level fields and message text. This closes that gap and gives the app-first surfaces one clearer day-2 workflow.

Validation

Ran serially with YOQ_SKIP_SLOW_TESTS=1:

• zig build test -Doptimize=ReleaseSafe -Dtest-filter='loadLocalRollbackSnapshot preserves service runtime fields while keeping original snapshot'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='formatAppStatusResponse summarizes latest release'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='writeHistoryJsonObject round-trips through remote parser'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='app rollback defaults to the previous successful release when release id is omitted'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='writeAppStatusJsonObject includes nested release and workload views'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='app rollback print returns the selected snapshot without creating a new release'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='appMatchesFilters applies failed and in-progress filters'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='writeHistoryJsonObject includes nested release markers'
• zig build test -Doptimize=ReleaseSafe -Dtest-filter='writeAppStatusJsonObject round-trips through remote parser'
• git diff --check

Risk

The main remaining gap is broader end-to-end local rollback integration coverage against a live running app. The rollback path is wired and covered through focused unit and route-flow tests, but I did not run a wider live-session smoke test in this slice.