Add scan.welshdag.trade explorer to chain 1404 (BlockDAG)

Also removes a zero-width space (U+200B) from the existing
rpc.bdagscan.com URL, which prevented it from parsing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: lukepashill-cyber

constants/additionalChainRegistry/chainid-1404.js

@@ -3,7 +3,7 @@ export const data = {
   "chain": "BDAG",
   "icon": "BDAG",
   "rpc": [
-    "​https://rpc.bdagscan.com",
+    "https://rpc.bdagscan.com",
   ],
   "faucets": [],
   "features": [{ "name": "EIP155" }, { "name": "EIP1559" }],
@@ -21,6 +21,11 @@ export const data = {
       "name": "BlockDAG Explorer",
       "url": "https://bdagscan.com/",
     },
+    {
+      "name": "WelshDAG Explorer",
+      "url": "https://scan.welshdag.trade",
+      "standard": "EIP3091",
+    },
   ],
   "status": "active"
 };