Method backend

src/models/ace_step/planner.cpp:1724–1724

    const AceStepAssets & assets() const noexcept { return *assets_; }
    const PlannerWeights & weights() const noexcept { return *weights_; }
    ggml_backend_t backend() const noexcept { return backend_; }
    core::BackendType backend_type() const noexcept { return backend_type_; }
    int threads() const noexcept { return threads_; }