fix: use spawn+manual read+wait instead of output() to avoid stdout pipe hang

apps/monitor/src/runner.rs

@@ -196,24 +196,51 @@ async fn run_curl(
 
     cmd.arg(url);
 
-    let output = tokio::time::timeout(
-        std::time::Duration::from_secs_f64(timeout_secs + 2.0),
-        cmd.output()
-    ).await
-        .map_err(|_| format!("timed out after {:.0}s", timeout_secs))?
-        .map_err(|e| format!("curl exec error: {e}"))?;
+    let mut child = cmd.spawn().map_err(|e| format!("curl spawn error: {e}"))?;
 
-    if !output.status.success() {
-        let stderr = String::from_utf8_lossy(&output.stderr).to_string();
-        let msg = match output.status.code() {
-            Some(28) => format!("timed out after {:.0}s", timeout_secs),
-            Some(6)  => "DNS lookup failed".to_string(),
-            Some(7)  => "connection refused".to_string(),
-            _        => stderr.trim().to_string(),
+    let stdout_handle = child.stdout.take();
+    let stderr_handle = child.stderr.take();
+
+    // Read stdout and stderr concurrently, then wait for process exit
+    let (stdout_bytes, stderr_bytes, status) = tokio::time::timeout(
+        std::time::Duration::from_secs_f64(timeout_secs + 2.0),
+        async {
+            let stdout_fut = async {
+                if let Some(mut out) = stdout_handle {
+                    let mut buf = Vec::new();
+                    tokio::io::AsyncReadExt::read_to_end(&mut out, &mut buf).await.ok();
+                    buf
+                } else { Vec::new() }
+            };
+            let stderr_fut = async {
+                if let Some(mut err) = stderr_handle {
+                    let mut buf = Vec::new();
+                    tokio::io::AsyncReadExt::read_to_end(&mut err, &mut buf).await.ok();
+                    buf
+                } else { Vec::new() }
+            };
+            let (out, err) = tokio::join!(stdout_fut, stderr_fut);
+            let status = child.wait().await;
+            (out, err, status)
+        }
+    ).await.map_err(|_| format!("timed out after {:.0}s", timeout_secs))?;
+
+    let exit_code = status.ok().and_then(|s| s.code()).unwrap_or(-1);
+
+    if exit_code != 0 {
+        let stderr = String::from_utf8_lossy(&stderr_bytes).to_string();
+        let msg = match exit_code {
+            28 => format!("timed out after {:.0}s", timeout_secs),
+            6  => "DNS lookup failed".to_string(),
+            7  => "connection refused".to_string(),
+            _  => stderr.trim().to_string(),
         };
         return Err(msg);
     }
 
+    struct FakeOutput { stdout: Vec<u8>, stderr: Vec<u8> }
+    let output = FakeOutput { stdout: stdout_bytes, stderr: stderr_bytes };
+
     // Parse curl output: headers then blank line then body
     let raw = String::from_utf8_lossy(&output.stdout).to_string();
     let mut parts = raw.splitn(2, "\r\n\r\n");