feat(core): switch to native fetch API for all HTTP requests

ts/bunq.classes.httpclient.ts

@@ -27,7 +27,7 @@ export class BunqHttpClient {
    * Make an API request to bunq
    */
   public async request<T = any>(options: IBunqRequestOptions): Promise<T> {
-    const url = `${this.context.baseUrl}${options.endpoint}`;
+    let url = `${this.context.baseUrl}${options.endpoint}`;
     
     // Prepare headers
     const headers = this.prepareHeaders(options);
@@ -45,47 +45,45 @@ export class BunqHttpClient {
       );
     }
 
-    // Make the request
-    const requestOptions: any = {
-      method: options.method === 'LIST' ? 'GET' : options.method,
-      headers: headers,
-      requestBody: body
-    };
-
+    // Handle query parameters
     if (options.params) {
-      const queryParams: { [key: string]: string } = {};
+      const queryParams = new URLSearchParams();
       Object.entries(options.params).forEach(([key, value]) => {
         if (value !== undefined && value !== null) {
-          queryParams[key] = String(value);
+          queryParams.append(key, String(value));
         }
       });
-      requestOptions.queryParams = queryParams;
+      const queryString = queryParams.toString();
+      if (queryString) {
+        url += '?' + queryString;
+      }
     }
 
+    // Make the request using native fetch
+    const fetchOptions: RequestInit = {
+      method: options.method === 'LIST' ? 'GET' : options.method,
+      headers: headers,
+      body: body
+    };
+
     try {
-      const response = await plugins.smartrequest.request(url, requestOptions);
+      const response = await fetch(url, fetchOptions);
+      
+      // Get response body as text
+      const responseText = await response.text();
       
       // Verify response signature if we have server public key
       if (this.context.serverPublicKey) {
         // Convert headers to string-only format
         const stringHeaders: { [key: string]: string } = {};
-        for (const [key, value] of Object.entries(response.headers)) {
-          if (typeof value === 'string') {
-            stringHeaders[key] = value;
-          } else if (Array.isArray(value)) {
-            stringHeaders[key] = value.join(', ');
-          }
-        }
-        
-        // Convert body to string if needed for signature verification
-        const bodyString = typeof response.body === 'string' 
-          ? response.body 
-          : JSON.stringify(response.body);
+        response.headers.forEach((value, key) => {
+          stringHeaders[key] = value;
+        });
         
         const isValid = this.crypto.verifyResponseSignature(
-          response.statusCode,
+          response.status,
           stringHeaders,
-          bodyString,
+          responseText,
           this.context.serverPublicKey
         );
         
@@ -99,17 +97,21 @@ export class BunqHttpClient {
         }
       }
 
-      // Parse response - smartrequest may already parse JSON automatically
+      // Parse response
       let responseData;
-      if (typeof response.body === 'string') {
+      if (responseText) {
         try {
-          responseData = JSON.parse(response.body);
+          responseData = JSON.parse(responseText);
         } catch (parseError) {
+          // If parsing fails and it's not a 2xx response, throw an HTTP error
+          if (!response.ok) {
+            throw new Error(`HTTP ${response.status}: ${response.statusText}`);
+          }
           throw new Error(`Failed to parse JSON response: ${parseError.message}`);
         }
       } else {
-        // Response is already parsed
-        responseData = response.body;
+        // Empty response body
+        responseData = {};
       }
       
       // Check for errors
@@ -117,6 +119,11 @@ export class BunqHttpClient {
         throw new BunqApiError(responseData.Error);
       }
 
+      // Check HTTP status
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}: ${response.statusText}`);
+      }
+
       return responseData;
     } catch (error) {
       if (error instanceof BunqApiError) {