Move activeConnections to Server

src/server.hpp

@@ -89,6 +89,7 @@ public:
   static void releaseBackToServer(std::unique_ptr<Connection> connection);
 
 private:
+  friend class Connection;
   /**
    * Private constructor - use create() factory method instead.
    *
@@ -105,6 +106,7 @@ private:
 
   // Connection management
   std::atomic<int64_t> connection_id_{0};
+  std::atomic<int> active_connections_{0};
 
   // Round-robin counter for connection distribution
   std::atomic<size_t> connection_distribution_counter_{0};