Phase 3c of migration #2: drop the Secret stanza from auth.yaml; the Middleware stays and references filebrowser-auth-infisical (synced from homelab/prod /filebrowser). ArgoCD prunes the old plaintext filebrowser-auth secret — the bcrypt htpasswd leaves git. Completes migration #2. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>