fix(node): warn when no foreign chain is configured

A node is expected to configure the chains the code supports, so an
empty section is a misconfiguration rather than a quiet path. The
startup probe is the only place that observes it.

Author: haiyuechen-nearone

crates/node/src/foreign_chain_probe.rs

@@ -17,7 +17,7 @@ use crate::metrics;
 /// serving, because a boot time blip should not take a chain out of signing.
 pub async fn run_startup_probe(foreign_chains: ForeignChainsConfig) {
     if foreign_chains.is_empty() {
-        debug!("no foreign chain is configured, skipping the RPC provider probe");
+        warn!("no foreign chain is configured: this node cannot verify foreign-chain transactions");
         return;
     }
 
@@ -80,7 +80,6 @@ fn log_report(report: &ProbeReport) {
     info!("foreign-chain RPC provider probe complete: {healthy}/{probed} providers healthy");
 }
 
-/// Publish healthy/Configured counts per chain
 fn publish_metrics(report: &ProbeReport) {
     let probed_chains: BTreeSet<dtos::ForeignChain> = report
         .rows()

crates/node/src/run.rs

@@ -209,7 +209,7 @@ pub async fn run_mpc_node(config: StartConfig) -> anyhow::Result<()> {
 
     let _web_server_join_handle = root_runtime.spawn(web_server);
 
-    // Detached and diagnostic only: reports which network each configured provider serves.
+    // Check number of healthy foreign chain RPC providers, detached and diagnostic only
     root_runtime.spawn(crate::foreign_chain_probe::run_startup_probe(
         node_config.foreign_chains.clone(),
     ));