Add DigiByte and Dash mainnet bitcoin-family RPC nodes.

DigiByte uses a tarball-install digibyted.Dockerfile (v9.26.3); Dash uses
dashpay/dashd:23.1.7. Both follow the dogecoind bitcoind pattern for RPC
auth, ZMQ, traefik, and x-upstreams wiring.

Co-authored-by: Cursor <cursoragent@cursor.com>

compose_registry.json

@@ -1918,6 +1918,34 @@
       "cronos-zkevm-testnet-external-node-pruned_db"
     ]
   },
+  {
+    "chain": "mainnet",
+    "client": "dashd",
+    "compose_file": "dash/dashd/dash-mainnet-dashd-full",
+    "features": [],
+    "network": "dash",
+    "node": null,
+    "relay": null,
+    "stack": null,
+    "type": "full",
+    "volumes": [
+      "dash-mainnet-dashd-full"
+    ]
+  },
+  {
+    "chain": "mainnet",
+    "client": "digibyted",
+    "compose_file": "digibyte/digibyted/digibyte-mainnet-digibyted-full",
+    "features": [],
+    "network": "digibyte",
+    "node": null,
+    "relay": null,
+    "stack": null,
+    "type": "full",
+    "volumes": [
+      "digibyte-mainnet-digibyted-full"
+    ]
+  },
   {
     "chain": "mainnet",
     "client": "dogecoind",