Add a thin, additive public facade over the engine (Council/Advisor/deliberate/stream/DeliberationResult), non-MainActor + Sendable, callable from any context. Direct-key and custom-endpoint escape hatches held transiently (no-trace), per-(backend,model) pricing override, and partial-failure reporting. Engine changes are additive seams only (persistence gates, transient keys/endpoints, price override); CouncilStore stays public. Ships LICENSE, README, and a 10-test suite including a leaves-no-trace invariant.