fix(cln): parse msat strings and fix default socket path

- CLN's listpeerchannels returns msat values as strings (e.g.
  "5000000msat"). as_u64() silently returned 0, making all
  balance assertions incorrect.
- Update default socket path to match docker-compose mount
  point (/tmp/cln-data/regtest/lightning-rpc).

Author: febyeji

tests/common/cln.rs

@@ -16,6 +16,17 @@ use serde_json::json;
 
 use super::external_node::{ExternalChannel, ExternalNode, TestFailure};
 
+/// Parse a CLN msat value which may be a plain integer or a string like "5000000msat".
+fn parse_cln_msat(val: &serde_json::Value) -> u64 {
+	if let Some(n) = val.as_u64() {
+		return n;
+	}
+	if let Some(s) = val.as_str() {
+		return s.trim_end_matches("msat").parse().unwrap_or(0);
+	}
+	0
+}
+
 pub(crate) struct TestClnNode {
 	client: Arc<LightningRPC>,
 	listen_addr: SocketAddress,
@@ -27,8 +38,8 @@ impl TestClnNode {
 	}
 
 	pub(crate) fn from_env() -> Self {
-		let sock =
-			std::env::var("CLN_SOCKET_PATH").unwrap_or_else(|_| "/tmp/lightning-rpc".to_string());
+		let sock = std::env::var("CLN_SOCKET_PATH")
+			.unwrap_or_else(|_| "/tmp/cln-data/regtest/lightning-rpc".to_string());
 		let listen_addr: SocketAddress = std::env::var("CLN_P2P_ADDR")
 			.unwrap_or_else(|_| "127.0.0.1:19846".to_string())
 			.parse()
@@ -307,8 +318,8 @@ impl ExternalNode for TestClnNode {
 				.as_str()
 				.ok_or_else(|| self.make_error("list_channels: missing channel_id".to_string()))?
 				.to_string();
-			let total_msat = ch["total_msat"].as_u64().unwrap_or(0);
-			let to_us_msat = ch["to_us_msat"].as_u64().unwrap_or(0);
+			let total_msat = parse_cln_msat(&ch["total_msat"]);
+			let to_us_msat = parse_cln_msat(&ch["to_us_msat"]);
 			let funding_txid = ch["funding_txid"].as_str().map(|s| s.to_string());
 			let state = ch["state"].as_str().unwrap_or("");
 			channels.push(ExternalChannel {