feat: add free_sd_images function to manage memory for C API (#1633)

src/stable-diffusion.cpp

@@ -5561,3 +5561,18 @@ SD_API bool generate_video(sd_ctx_t* sd_ctx,
     }
     return true;
 }
+
+SD_API void free_sd_images(sd_image_t* result_images, int num_images) {
+    if (result_images == nullptr) {
+        return;
+    }
+
+    for (int i = 0; i < num_images; ++i) {
+        if (result_images[i].data != nullptr) {
+            free(result_images[i].data);
+            result_images[i].data = nullptr;
+        }
+    }
+
+    free(result_images);
+}