feat: add gateway lifecycle controls

crates/cli/Cargo.toml

@@ -46,6 +46,7 @@ hyper = "1"
 hyper-util = { version = "0.1", features = ["tokio"] }
 dialoguer = { version = "0.11", default-features = false, features = ["password"] }
 jsonschema = { version = "0.46.6", default-features = false }
+listeners = "0.4"
 log = { version = "0.4", features = ["kv"] }
 percent-encoding = "2"
 reqwest = { version = "0.12", default-features = false, features = ["charset", "http2", "json", "rustls-tls-native-roots", "stream"] }
@@ -72,6 +73,9 @@ zstd = "0.13"
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"
 
+[target.'cfg(any(unix, windows))'.dependencies]
+sysinfo = { version = "0.38", default-features = false, features = ["system"] }
+
 [target.'cfg(windows)'.dependencies]
 windows-sys = { version = "0.61", features = ["Win32_Foundation", "Win32_Security", "Win32_Security_Authorization", "Win32_Storage_FileSystem", "Win32_System_Diagnostics_ToolHelp", "Win32_System_JobObjects", "Win32_System_SystemInformation", "Win32_System_Threading"] }
 

crates/cli/src/bootstrap/mod.rs

@@ -571,8 +571,33 @@ pub(crate) fn plugin_idle_timeout() -> Result<Duration, String> {
     Ok(Duration::from_secs(seconds))
 }
 
+/// Returns the persistent MCP gateway heartbeat interval.
 pub(crate) fn plugin_heartbeat_interval() -> Result<Duration, String> {
-    Ok((plugin_idle_timeout()? / 3).clamp(Duration::from_millis(100), Duration::from_secs(30)))
+    let idle_timeout = plugin_idle_timeout()?;
+    let Ok(raw) = env::var(crate::configuration::PLUGIN_HEARTBEAT_INTERVAL_ENV) else {
+        return Ok((idle_timeout / 3).clamp(Duration::from_millis(100), Duration::from_secs(3)));
+    };
+    let seconds = raw.parse::<u64>().map_err(|error| {
+        format!(
+            "{} must be a positive integer: {error}",
+            crate::configuration::PLUGIN_HEARTBEAT_INTERVAL_ENV
+        )
+    })?;
+    if seconds == 0 {
+        return Err(format!(
+            "{} must be greater than 0",
+            crate::configuration::PLUGIN_HEARTBEAT_INTERVAL_ENV
+        ));
+    }
+    let heartbeat_interval = Duration::from_secs(seconds);
+    if heartbeat_interval >= idle_timeout {
+        return Err(format!(
+            "{} must be shorter than {}",
+            crate::configuration::PLUGIN_HEARTBEAT_INTERVAL_ENV,
+            crate::configuration::PLUGIN_IDLE_TIMEOUT_ENV
+        ));
+    }
+    Ok(heartbeat_interval)
 }
 
 #[cfg(test)]