refactor: propagate error from Client::builder instead of silent fallback

Address review feedback: `unwrap_or_else(|_| Client::new())` silently
drops the configured timeout on builder failure. Change `new()` to
return `Result<Self>` and propagate with `?` instead.

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <[email protected]>
Co-Authored-By: Happy <[email protected]>

src/tunnel/custom.rs

@@ -1,6 +1,6 @@
 //! Custom tunnel via an arbitrary shell command.
 
-use anyhow::{Result, bail};
+use anyhow::{Context, Result, bail};
 use tokio::io::AsyncBufReadExt;
 use tokio::process::Command;
 
@@ -35,18 +35,19 @@ impl CustomTunnel {
         start_command: String,
         health_url: Option<String>,
         url_pattern: Option<String>,
-    ) -> Self {
-        Self {
+    ) -> Result<Self> {
+        let http_client = reqwest::Client::builder()
+            .timeout(std::time::Duration::from_secs(5))
+            .build()
+            .context("failed to create HTTP client for tunnel health checks")?;
+        Ok(Self {
             start_command,
             health_url,
             url_pattern,
             proc: new_shared_process(),
             url: new_shared_url(),
-            http_client: reqwest::Client::builder()
-                .timeout(std::time::Duration::from_secs(5))
-                .build()
-                .unwrap_or_else(|_| reqwest::Client::new()),
-        }
+            http_client,
+        })
     }
 }
 
@@ -178,7 +179,7 @@ mod tests {
 
     #[tokio::test]
     async fn empty_command_returns_error() {
-        let tunnel = CustomTunnel::new("   ".into(), None, None);
+        let tunnel = CustomTunnel::new("   ".into(), None, None).unwrap();
         let result = tunnel.start("127.0.0.1", 8080).await;
         assert!(result.is_err());
         assert!(
@@ -191,7 +192,7 @@ mod tests {
 
     #[tokio::test]
     async fn start_without_pattern_returns_local() {
-        let tunnel = CustomTunnel::new("sleep 1".into(), None, None);
+        let tunnel = CustomTunnel::new("sleep 1".into(), None, None).unwrap();
         let url = tunnel.start("127.0.0.1", 4455).await.unwrap();
         assert_eq!(url, "http://127.0.0.1:4455");
         tunnel.stop().await.unwrap();
@@ -203,7 +204,8 @@ mod tests {
             "echo https://public.example".into(),
             None,
             Some("public.example".into()),
-        );
+        )
+        .unwrap();
         let url = tunnel.start("localhost", 9999).await.unwrap();
         assert_eq!(url, "https://public.example");
         tunnel.stop().await.unwrap();
@@ -218,7 +220,8 @@ mod tests {
             r"printf http://internal:1234\nhttps://real.tunnel.io/abc\n".into(),
             None,
             Some("tunnel.io".into()),
-        );
+        )
+        .unwrap();
         let url = tunnel.start("localhost", 9999).await.unwrap();
         assert_eq!(url, "https://real.tunnel.io/abc");
         tunnel.stop().await.unwrap();
@@ -230,7 +233,8 @@ mod tests {
             "echo http://{host}:{port}".into(),
             None,
             Some("http://".into()),
-        );
+        )
+        .unwrap();
         let url = tunnel.start("10.1.2.3", 4321).await.unwrap();
         assert_eq!(url, "http://10.1.2.3:4321");
         tunnel.stop().await.unwrap();
@@ -243,7 +247,8 @@ mod tests {
             "sleep 1".into(),
             Some("http://192.0.2.1:9999/healthz".into()),
             None,
-        );
+        )
+        .unwrap();
         assert!(
             !tunnel.health_check().await,
             "Health check should fail for unreachable URL"

src/tunnel/mod.rs

@@ -171,7 +171,7 @@ pub fn create_tunnel(config: &TunnelProviderConfig) -> Result<Option<Box<dyn Tun
                 cu.start_command.clone(),
                 cu.health_url.clone(),
                 cu.url_pattern.clone(),
-            ))))
+            )?)))
         }
 
         other => bail!(