fix puma_server? - check $PROGRAM_NAME, not defined?(Puma::Server)

Just checking defined?(::Puma::Server) is unreliable because Puma might
be installed but not running. Check $PROGRAM_NAME.include?("puma") to
verify we're actually running as a puma process.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: ndbroadbent

lib/log_struct/concerns/configuration.rb

@@ -132,7 +132,7 @@ def console_process?
         sig { returns(T::Boolean) }
         def server_process?
           return true if logstruct_server_mode?
-          return true if defined?(::Puma::Server)
+          return true if puma_server?
           return true if defined?(::Unicorn::HttpServer)
           return true if defined?(::Thin::Server)
           return true if defined?(::Falcon::Server)
@@ -142,6 +142,13 @@ def server_process?
           false
         end
 
+        sig { returns(T::Boolean) }
+        def puma_server?
+          # Just checking defined?(::Puma::Server) is not reliable - Puma might be installed
+          # but not running. Check $PROGRAM_NAME to verify we're actually running puma.
+          $PROGRAM_NAME.include?("puma")
+        end
+
         sig { returns(T::Boolean) }
         def sidekiq_server?
           !!(defined?(::Sidekiq) && ::Sidekiq.respond_to?(:server?) && ::Sidekiq.server?)