Expose ZMQ block notifications toggle in config

New 'zmq-enabled' boolean (default true) makes the entrypoint
export BITCOIN_ZMQ_BLOCK=tcp://<bitcoind-host>:28332, which
kamado-api's zmqmon subscribes to for sub-second chain refresh
on the dashboard. Disable it if your bitcoind doesn't have
zmqpubhashblock exposed.

scripts/procedures/getConfig.ts

@@ -129,6 +129,13 @@ export const getConfig: T.ExpectedExports.getConfig = compat.getConfig({
     "range": "[0,*)",
     "integral": true,
   },
+  "zmq-enabled": {
+    "type": "boolean",
+    "name": "Enable ZMQ Block Notifications",
+    "description":
+      "Subscribe to Bitcoin Core's hashblock ZMQ topic for sub-second chain refresh on the dashboard. Requires zmqpubhashblock to be enabled on your bitcoind — the default StartOS bitcoind package exposes it on tcp://bitcoind.embassy:28332.",
+    "default": true,
+  },
   "log-level": {
     "type": "enum",
     "name": "Log Level",