fix(v1.0.1): VDE-014/015/016 — STL API cleanup + ssi_boolean fixes

VDE-014 (High): Remove duplicate void write_stl/write_stl_ascii declarations
VDE-015 (Medium): Fix Vector3F→Vector3f, Point3F→Point3f case sensitivity
VDE-016 (High): Add forward declarations for face_bounds/face_normal/SSICurveData
  in ssi_boolean.cpp — fixes two-phase name lookup in GCC

include/vde/foundation/io_stl.h

@@ -91,7 +91,6 @@ std::vector<StlTriangle> read_stl(const std::string& filepath);
  * @see read_stl, write_stl_ascii
  * @ingroup foundation
  */
-void write_stl(const std::string& filepath, const std::vector<StlTriangle>& tris);
 bool write_stl(const std::string& filepath, const std::vector<StlTriangle>& tris);
 
 /**
@@ -115,7 +114,6 @@ bool write_stl(const std::string& filepath, const std::vector<StlTriangle>& tris
  * @see read_stl, write_stl
  * @ingroup foundation
  */
-void write_stl_ascii(const std::string& filepath, const std::vector<StlTriangle>& tris);
 bool write_stl_ascii(const std::string& filepath, const std::vector<StlTriangle>& tris);
 
 /**
@@ -124,8 +122,8 @@ bool write_stl_ascii(const std::string& filepath, const std::vector<StlTriangle>
  * 用于与 float 网格数据直接交互，避免 double↔float 显式转换。
  */
 struct StlTrianglef {
-    Vector3F normal;
-    Point3F  v0, v1, v2;
+    Vector3f normal;
+    Point3f  v0, v1, v2;
 };
 
 /// 转换 double → float 精度