fix(windows): add memset_explicit symbol export for mingw cross-compilation

- Add __declspec(dllexport) to memset_explicit in memset_s_shim.c
- Explicitly link memset_shim library in build.rs for Windows MinGW target
- Fixes undefined reference to memset_explicit when building for x86_64-pc-windows-gnu

src-tauri/build.rs

@@ -13,6 +13,8 @@ fn main() {
             .file("memset_s_shim.c")
             .compile("memset_shim");
         println!("cargo:rerun-if-changed=memset_s_shim.c");
+        // Explicitly link the shim library
+        println!("cargo:rustc-link-lib=static=memset_shim");
     }
 
     tauri_build::build()

src-tauri/memset_s_shim.c

@@ -6,7 +6,13 @@
 
 #include <string.h>
 
-void memset_explicit(void *dest, int val, size_t n) {
+#ifdef _WIN32
+#define EXPORT __declspec(dllexport)
+#else
+#define EXPORT
+#endif
+
+EXPORT void memset_explicit(void *dest, int val, size_t n) {
     volatile unsigned char *p = (volatile unsigned char *)dest;
     while (n--) {
         *p++ = (unsigned char)val;