feat: use DragonX DNS seed nodes, pass -maxconnections to daemon, show sync speed

- Replace hardcoded IP addnodes with node.dragonx.is, node1–4.dragonx.is
  in both daemon launch params and auto-generated DRAGONX.conf
- Add max_connections setting (persisted, default 0 = daemon default);
  passed as -maxconnections= flag to dragonxd on startup
- Show blocks/sec in status bar during sync with exponential smoothing
  (e.g. "Syncing 45.2% (12340 left, 85 blk/s)")

src/daemon/embedded_daemon.h

@@ -152,6 +152,11 @@ public:
     void setDebugCategories(const std::set<std::string>& cats) { debug_categories_ = cats; }
     const std::set<std::string>& getDebugCategories() const { return debug_categories_; }
 
+    /**
+     * @brief Set maximum peer connections (0 = use daemon default)
+     */
+    void setMaxConnections(int v) { max_connections_ = v; }
+
     /**
      * @brief Request a blockchain rescan on the next daemon start
      */
@@ -194,6 +199,7 @@ private:
     std::thread monitor_thread_;
     std::atomic<bool> should_stop_{false};
     std::set<std::string> debug_categories_;
+    int max_connections_ = 0;  // 0 = daemon default
     std::atomic<int> crash_count_{0};  // consecutive crash counter
     std::atomic<bool> rescan_on_next_start_{false};  // -rescan flag for next start
 };