feat(ancpi): test EditCartItemJson + SearchEstate with AJAX headers

src/modules/parcel-sync/services/epay-client.ts

@@ -256,6 +256,22 @@ export class EpayClient {
     return String(response.data ?? "");
   }
 
+  /* ── Raw POST (for endpoint discovery) ──────────────────── */
+
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  async postRaw(url: string, body: string, extraHeaders?: Record<string, string>): Promise<any> {
+    const response = await this.client.post(url, body, {
+      headers: {
+        "Content-Type": "application/x-www-form-urlencoded",
+        ...extraHeaders,
+      },
+      timeout: DEFAULT_TIMEOUT_MS,
+      maxRedirects: 5,
+      validateStatus: () => true,
+    });
+    return response.data;
+  }
+
   /* ── Credits ───────────────────────────────────────────────── */
 
   async getCredits(): Promise<number> {