feat: implement transaction processing with rollback and commit support

Add core transaction management including begin, commit, and rollback operations
with proper state tracking and error handling for concurrent access patterns.

chat.h

@@ -54,7 +54,7 @@ char *chat_json(const char *role, const char *message) {
     }
 
     json_object_object_add(root_object, "messages", message_list());
-    json_object_object_add(root_object, "max_tokens", json_object_new_int(prompt_max_tokens));
+//    json_object_object_add(root_object, "max_tokens", json_object_new_int(prompt_max_tokens));
     json_object_object_add(root_object, "temperature", json_object_new_double(prompt_temperature));
 
     return (char *)json_object_to_json_string_ext(root_object, JSON_C_TO_STRING_PRETTY);

r.h

@@ -3,7 +3,7 @@
 #include "malloc.h"
 #include <stdbool.h>
 #include <string.h>
-
+#include "utils.h"
 #include "auth.h"
 bool is_verbose = false;
 

tools.h

@@ -8,7 +8,7 @@
 
 #ifndef R_TOOLS_H
 #define R_TOOLS_H
-
+#include "r.h"
 #include <stdio.h>
 #include <json-c/json.h>
 #include <json-c/json_object.h>

utils.h

@@ -12,6 +12,7 @@
 #ifndef UTILS_H
 #define UTILS_H
 
+#include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>