chore(client): send user-agent header

Author: stainless-app[bot]

lib/lithic/internal/transport/base_client.rb

@@ -201,7 +201,8 @@ def initialize(
             self.class::PLATFORM_HEADERS,
             {
               "accept" => "application/json",
-              "content-type" => "application/json"
+              "content-type" => "application/json",
+              "user-agent" => user_agent
             },
             headers
           )
@@ -219,6 +220,11 @@ def initialize(
         # @return [Hash{String=>String}]
         private def auth_headers = {}
 
+        # @api private
+        #
+        # @return [String]
+        private def user_agent = "#{self.class.name}/Ruby #{Lithic::VERSION}"
+
         # @api private
         #
         # @return [String]

rbi/lithic/internal/transport/base_client.rbi

@@ -176,6 +176,11 @@ module Lithic
         private def auth_headers
         end
 
+        # @api private
+        sig { returns(String) }
+        private def user_agent
+        end
+
         # @api private
         sig { returns(String) }
         private def generate_idempotency_key

sig/lithic/internal/transport/base_client.rbs

@@ -87,6 +87,8 @@ module Lithic
 
         private def auth_headers: -> ::Hash[String, String]
 
+        private def user_agent: -> String
+
         private def generate_idempotency_key: -> String
 
         private def build_request: (