//! Shared scaffolding for cloud substrates (Render, Vercel, …).
//!
//! Only verified-identical machinery lives here — credential resolution,
//! operator-side prepare, the health-gate poll, and the spend line. Each
//! provider keeps its own error type, codes, and deploy semantics; the shared
//! helpers return neutral data the provider maps to its own fault, so
//! per-provider error codes stay distinct (ARCHITECTURE.md §2). Deploy/lifecycle
//! (the REST clients, teardown verification, namespace shape) is deliberately
//! NOT abstracted here — it differs materially between providers and has too few
//! instances to generalise safely.