Add machine workshop, typed logic, mechanics and sensor-driven ECUs

include/FluidSim/Component.hpp

@@ -13,6 +13,7 @@ struct Port {
     float gamma_value{1.4f}, gas_constant_value{287.0f};
     float air_fraction{1.0f};
     float fuel_fraction{};
+    float fuel_equivalent_fraction{}; // fuel origin, including fuel already burned
     float* owner_energy{};
     float* owner_air_mass{};
     float* owner_exhaust_mass{};
@@ -25,6 +26,8 @@ class Component {
 public:
     virtual ~Component() = default;
     virtual std::vector<Port*> ports() = 0;
+    // Optional actuation at each CFL substep, before boundary fluxes are resolved.
+    virtual void prepare_step(float /*dt*/) {}
     virtual void update_state(float dt) = 0;
 };