Constraint: Must preserve current exchange-rate logic, same-group routing boundary, and temporary image-file behavior while fixing UX-visible inconsistencies.
Rejected: Large frontend chunk refactor | introduced risky circular chunking and did not improve deliverability for this rollout.
Confidence: medium
Scope-risk: moderate
Directive: Keep channel failover constrained to the selected group and preserve Beijing-day semantics for user cache dashboard metrics.
Tested: go test ./controller ./model ./service ./common -count=1; npm run build; remote smoke on source deployment at http://38.76.218.56:18081/ plus /api/status and /api/image-studio/settings.
Not-tested: Browser-driven end-to-end verification of every console page interaction.
