[security] scale-zero-pg compute pods: container-level restricted securityContext #2564

packages/scale-zero-pg/gateway/internal/appdb/render.go (around :155 and :329) sets only a pod-level seccomp profile on compute pods. Bring them to the same restricted profile as operator-rendered app/function containers: allowPrivilegeEscalation:false, capabilities.drop:[ALL], seccompProfile:RuntimeDefault, runAsNonRoot:true, checked by the pod-security-admission restricted evaluator against the real render. Found in code review of the pod-hardening PR (out of its scope).