fix(build): add memset_shim for Windows MinGW and rpm for Linux ARM64

src-tauri/src/memset_shim.rs

@@ -0,0 +1,13 @@
+/// Windows MinGW memset_explicit shim
+/// libsodium-sys-stable expects memset_explicit which isn't available in MinGW
+/// This provides a compatible implementation
+
+#[cfg(target_os = "windows")]
+#[no_mangle]
+pub extern "C" fn memset_explicit(dest: *mut u8, val: i32, n: usize) {
+    unsafe {
+        for i in 0..n {
+            *dest.add(i) = val as u8;
+        }
+    }
+}