Update generate pipeline to add OpenAI api as an additional backend (for comparison testing), add brewery coordinates (#244)

* add brewery coordinates

* Add openai mode

* Add coordinates to schema

* Fix C++ review findings in pipeline: k-prefixed enum values, include ordering, populated validation error messages, conventional const notation, and endl replaced with newline

tooling/pipeline/includes/web_client/web_client.h

@@ -7,6 +7,8 @@
  */
 
 #include <string>
+#include <utility>
+#include <vector>
 
 /**
  * @brief Abstract web client interface.
@@ -23,6 +25,20 @@ class WebClient {
     */
    virtual std::string Get(const std::string& url) = 0;
 
+   /**
+    * @brief Executes an HTTP POST request with a JSON body.
+    *
+    * @param url Request URL.
+    * @param body Request body (sent as-is; callers are responsible for
+    * providing valid JSON when the target API expects it).
+    * @param headers Additional request headers (e.g. authentication),
+    * sent alongside a fixed "Content-Type: application/json" header.
+    * @return Response body.
+    */
+   virtual std::string Post(
+       const std::string& url, const std::string& body,
+       const std::vector<std::pair<std::string, std::string>>& headers) = 0;
+
    /**
     * @brief URL-encodes a string value.
     *