feat: add candidate FreeCAD naming SDK and attachment oracles

Build and verify the candidate-only FreeCAD naming bridge and OCCT worker path, including three-stage StringHasher restoration. Add Datum, ShapeBinder, attachment-mode, and PartDesign structure oracles plus offline SDK build plans and CI boundary checks.

native/freecad-naming-probe/shims/App/Document.h

@@ -0,0 +1,19 @@
+#ifndef SRC_APP_DOCUMENT_H_
+#define SRC_APP_DOCUMENT_H_
+
+#include <App/DocumentObject.h>
+
+namespace App {
+
+class Document
+{
+public:
+    DocumentObject* getObjectByID(long) const
+    {
+        return nullptr;
+    }
+};
+
+}  // namespace App
+
+#endif