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/config/settings.h

@@ -165,6 +165,10 @@ public:
     bool getStopExternalDaemon() const { return stop_external_daemon_; }
     void setStopExternalDaemon(bool v) { stop_external_daemon_ = v; }
 
+    // Daemon — maximum peer connections (0 = daemon default)
+    int getMaxConnections() const { return max_connections_; }
+    void setMaxConnections(int v) { max_connections_ = std::max(0, v); }
+
     // Verbose diagnostic logging (connection attempts, daemon state, port owner, etc.)
     bool getVerboseLogging() const { return verbose_logging_; }
     void setVerboseLogging(bool v) { verbose_logging_ = v; }
@@ -303,6 +307,7 @@ private:
     bool pin_enabled_ = false;
     bool keep_daemon_running_ = false;
     bool stop_external_daemon_ = false;
+    int  max_connections_ = 0;  // 0 = daemon default
     bool verbose_logging_ = false;
     std::set<std::string> debug_categories_;
     bool theme_effects_enabled_ = true;