cc-ci-upgrade-all now reads an optional EnvironmentFile so the weekly run can switch backend/model (e.g. LOOP_BACKEND=opencode LOOP_MODEL=opencode-go/glm-5.2) without a rebuild. Absent file → claude/sonnet (unchanged). Built+switched on cc-ci-orchestrator-hetzner, host verified healthy. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>