Add American V8 preset, carb fuel transport, and adaptive desktop audio

include/FluidSim/TwoStrokeCylinder.hpp

@@ -5,6 +5,8 @@
 
 namespace fluidsim::port {
 
+class Carburetor;
+
 // Two-stroke variant of the reciprocating cylinder model. The shared four-
 // stroke implementation supplies geometry, state balance, and combustion
 // parameters; cycle events and pumping torque are specialized here.
@@ -19,6 +21,7 @@ public:
     float exhaust_open() const { return 180.0f - exhaust_duration_ * 0.5f; }
     float exhaust_close() const { return 180.0f + exhaust_duration_ * 0.5f; }
     void set_crankcase(Crankcase& crankcase) { crankcase_ = &crankcase; }
+    void set_carburetor(Carburetor& carburetor) { carburetor_ = &carburetor; }
     float transfer_width{.050f}, exhaust_width{.036f};
     float minimum_burn_seconds{.0008f};
     std::uint64_t combustion_count() const { return combustion_count_; }
@@ -29,6 +32,7 @@ public:
 private:
     float transfer_duration_{}, exhaust_duration_{};
     Crankcase* crankcase_{};
+    Carburetor* carburetor_{};
 
     float active_burn_duration_{60};
     float current_rpm_{};