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)")

res/ObsidianDragon.manifest

@@ -5,7 +5,7 @@
   <assemblyIdentity
     type="win32"
     name="DragonX.ObsidianDragon.Wallet"
-    version="1.1.1.0"
+    version="1.2.0.0"
     processorArchitecture="amd64"
   />