Completed refactoring to separate nip files, and updating build.sh

tests/http_test.c

@@ -9,8 +9,9 @@
 #include <curl/curl.h>
 
 // Callback to write received data
-static size_t WriteCallback(void *contents, size_t size, size_t nmemb, char *userp) {
+static size_t WriteCallback(void *contents, size_t size, size_t nmemb, void *userp) {
     size_t realsize = size * nmemb;
+    (void)userp; // Mark parameter as deliberately unused
     printf("%.*s", (int)realsize, (char*)contents);
     return realsize;
 }
@@ -30,7 +31,7 @@ int main() {
         curl_easy_setopt(curl, CURLOPT_URL, "https://google.com");
         
         // Set callback for received data
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
+        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, (curl_write_callback)WriteCallback);
         
         // Follow redirects
         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);