Restructure C++ core into cpp module and package bindings.

Move the pricing engine sources out of src/ into cpp/, add the closed-form engine and pybind wiring, and align tests/build targets with the new project layout.

Made-with: Cursor

cpp/DBIngest.hpp

@@ -0,0 +1,28 @@
+/**
+ * @file DBIngest.hpp
+ * @brief PostgreSQL helpers to load market objects (work in progress).
+ */
+
+#ifndef QUANTENGINE_DBINGEST_HPP
+#define QUANTENGINE_DBINGEST_HPP
+
+#include <pqxx/pqxx>
+
+#include "VolatilitySurface.hpp"
+#include "YieldCurve.hpp"
+
+/**
+ * @brief Connects to Postgres via libpqxx and queries quotes for surface building.
+ */
+class DBIngest {
+
+    bool connect();
+    bool disconnect();
+    bool update(VolatilitySurface& surface);
+    bool update(YieldCurve& yield_curve);
+private:
+    pqxx::connection connection_;
+};
+
+
+#endif //QUANTENGINE_DBINGEST_HPP