Pass NATS credentials explicitly: async-nats ignores userinfo in the URL

async_nats::connect() silently drops user:pass embedded in NATS_URL,
so the server rejected every connection with an authorization violation.
Parse the URL and feed credentials through ConnectOptions instead.

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

src/main.rs

@@ -32,7 +32,17 @@ async fn main() -> anyhow::Result<()> {
     let nats_url =
         std::env::var("NATS_URL").unwrap_or_else(|_| "nats://127.0.0.1:4222".to_string());
     tracing::info!(%nats_url, "connecting to NATS");
-    let nats = async_nats::connect(&nats_url).await?;
+    // async-nats does not honor userinfo embedded in the URL, so pass any
+    // credentials explicitly via ConnectOptions.
+    let parsed = url::Url::parse(&nats_url)?;
+    let mut nats_opts = async_nats::ConnectOptions::new();
+    if !parsed.username().is_empty() {
+        nats_opts = nats_opts.user_and_password(
+            parsed.username().to_string(),
+            parsed.password().unwrap_or_default().to_string(),
+        );
+    }
+    let nats = nats_opts.connect(&nats_url).await?;
 
     let database_url = std::env::var("DATABASE_URL")
         .unwrap_or_else(|_| "postgres://cnats:cnats@127.0.0.1:5432/cnats".to_string());