feat: Improve service manager testing and error handling

- Add comprehensive testing instructions to README.
- Improve error handling in examples to prevent crashes.
- Enhance launchctl error handling for production safety.
- Improve zinit error handling for production safety.
- Remove obsolete plan_to_fix.md file.
- Update Rhai integration tests for improved robustness.
- Improve service manager creation on Linux with systemd fallback.

service_manager/src/launchctl.rs

@@ -6,10 +6,25 @@ use std::path::PathBuf;
 use tokio::process::Command;
 use tokio::runtime::Runtime;
 
-// Shared runtime for async operations
-static ASYNC_RUNTIME: Lazy<Runtime> = Lazy::new(|| {
-    Runtime::new().expect("Failed to create async runtime for LaunchctlServiceManager")
-});
+// Shared runtime for async operations - production-safe initialization
+static ASYNC_RUNTIME: Lazy<Option<Runtime>> = Lazy::new(|| Runtime::new().ok());
+
+/// Get the async runtime, creating a temporary one if the static runtime failed
+fn get_runtime() -> Result<Runtime, ServiceManagerError> {
+    // Try to use the static runtime first
+    if let Some(_runtime) = ASYNC_RUNTIME.as_ref() {
+        // We can't return a reference to the static runtime because we need ownership
+        // for block_on, so we create a new one. This is a reasonable trade-off for safety.
+        Runtime::new().map_err(|e| {
+            ServiceManagerError::Other(format!("Failed to create async runtime: {}", e))
+        })
+    } else {
+        // Static runtime failed, try to create a new one
+        Runtime::new().map_err(|e| {
+            ServiceManagerError::Other(format!("Failed to create async runtime: {}", e))
+        })
+    }
+}
 
 #[derive(Debug)]
 pub struct LaunchctlServiceManager {
@@ -221,8 +236,9 @@ impl ServiceManager for LaunchctlServiceManager {
     }
 
     fn start(&self, config: &ServiceConfig) -> Result<(), ServiceManagerError> {
-        // Use the shared runtime for async operations
-        ASYNC_RUNTIME.block_on(async {
+        // Use production-safe runtime for async operations
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             let label = self.get_service_label(&config.name);
 
             // Check if service is already loaded
@@ -249,7 +265,8 @@ impl ServiceManager for LaunchctlServiceManager {
     }
 
     fn start_existing(&self, service_name: &str) -> Result<(), ServiceManagerError> {
-        ASYNC_RUNTIME.block_on(async {
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             let label = self.get_service_label(service_name);
             let plist_path = self.get_plist_path(service_name);
 
@@ -300,8 +317,9 @@ impl ServiceManager for LaunchctlServiceManager {
         // First start the service
         self.start(config)?;
 
-        // Then wait for confirmation using the shared runtime
-        ASYNC_RUNTIME.block_on(async {
+        // Then wait for confirmation using production-safe runtime
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             self.wait_for_service_status(&config.name, timeout_secs)
                 .await
         })
@@ -315,15 +333,17 @@ impl ServiceManager for LaunchctlServiceManager {
         // First start the existing service
         self.start_existing(service_name)?;
 
-        // Then wait for confirmation using the shared runtime
-        ASYNC_RUNTIME.block_on(async {
+        // Then wait for confirmation using production-safe runtime
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             self.wait_for_service_status(service_name, timeout_secs)
                 .await
         })
     }
 
     fn stop(&self, service_name: &str) -> Result<(), ServiceManagerError> {
-        ASYNC_RUNTIME.block_on(async {
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             let _label = self.get_service_label(service_name);
             let plist_path = self.get_plist_path(service_name);
 
@@ -359,7 +379,8 @@ impl ServiceManager for LaunchctlServiceManager {
     }
 
     fn status(&self, service_name: &str) -> Result<ServiceStatus, ServiceManagerError> {
-        ASYNC_RUNTIME.block_on(async {
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             let label = self.get_service_label(service_name);
             let plist_path = self.get_plist_path(service_name);
 
@@ -397,7 +418,8 @@ impl ServiceManager for LaunchctlServiceManager {
         service_name: &str,
         lines: Option<usize>,
     ) -> Result<String, ServiceManagerError> {
-        ASYNC_RUNTIME.block_on(async {
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             let log_path = self.get_log_path(service_name);
 
             if !log_path.exists() {
@@ -421,7 +443,8 @@ impl ServiceManager for LaunchctlServiceManager {
     }
 
     fn list(&self) -> Result<Vec<String>, ServiceManagerError> {
-        ASYNC_RUNTIME.block_on(async {
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             let list_output = self.run_launchctl(&["list"]).await?;
 
             let services: Vec<String> = list_output
@@ -456,8 +479,9 @@ impl ServiceManager for LaunchctlServiceManager {
             );
         }
 
-        // Remove the plist file using the shared runtime
-        ASYNC_RUNTIME.block_on(async {
+        // Remove the plist file using production-safe runtime
+        let runtime = get_runtime()?;
+        runtime.block_on(async {
             let plist_path = self.get_plist_path(service_name);
             if plist_path.exists() {
                 tokio::fs::remove_file(&plist_path).await?;