feat: Add herodo package to workspace

- Added the `herodo` package to the workspace.
- Updated the MONOREPO_CONVERSION_PLAN.md to reflect
  the completion of the herodo package conversion.
- Updated README.md and build_herodo.sh to reflect the
  new package structure.
- Created herodo/Cargo.toml, herodo/README.md,
  herodo/src/main.rs, herodo/src/lib.rs, and
  herodo/tests/integration_tests.rs and
  herodo/tests/unit_tests.rs.

herodo/src/lib.rs

@@ -0,0 +1,127 @@
+//! Herodo - A Rhai script executor for SAL
+//!
+//! This library loads the Rhai engine, registers all SAL modules,
+//! and executes Rhai scripts from a specified directory in sorted order.
+
+use rhai::Engine;
+use std::error::Error;
+use std::fs;
+use std::path::{Path, PathBuf};
+use std::process;
+
+/// Run the herodo script executor with the given script path
+///
+/// # Arguments
+///
+/// * `script_path` - Path to a Rhai script file or directory containing Rhai scripts
+///
+/// # Returns
+///
+/// Result indicating success or failure
+pub fn run(script_path: &str) -> Result<(), Box<dyn Error>> {
+    let path = Path::new(script_path);
+
+    // Check if the path exists
+    if !path.exists() {
+        eprintln!("Error: '{}' does not exist", script_path);
+        process::exit(1);
+    }
+
+    // Create a new Rhai engine
+    let mut engine = Engine::new();
+
+    // Register println function for output
+    engine.register_fn("println", |s: &str| println!("{}", s));
+
+    // Register all SAL modules with the engine
+    sal::rhai::register(&mut engine)?;
+
+    // Collect script files to execute
+    let script_files: Vec<PathBuf> = if path.is_file() {
+        // Single file
+        if let Some(extension) = path.extension() {
+            if extension != "rhai" {
+                eprintln!("Warning: '{}' does not have a .rhai extension", script_path);
+            }
+        }
+        vec![path.to_path_buf()]
+    } else if path.is_dir() {
+        // Directory - collect all .rhai files recursively and sort them
+        let mut files = Vec::new();
+        collect_rhai_files(path, &mut files)?;
+        
+        if files.is_empty() {
+            eprintln!("No .rhai files found in directory: {}", script_path);
+            process::exit(1);
+        }
+        
+        // Sort files for consistent execution order
+        files.sort();
+        
+        files
+    } else {
+        eprintln!("Error: '{}' is neither a file nor a directory", script_path);
+        process::exit(1);
+    };
+
+    println!("Found {} Rhai script{} to execute:",
+             script_files.len(),
+             if script_files.len() == 1 { "" } else { "s" });
+    
+    // Execute each script in sorted order
+    for script_file in script_files {
+        println!("\nExecuting: {}", script_file.display());
+        
+        // Read the script content
+        let script = fs::read_to_string(&script_file)?;
+        
+        // Execute the script
+        match engine.eval::<rhai::Dynamic>(&script) {
+            Ok(result) => {
+                println!("Script executed successfully");
+                if !result.is_unit() {
+                    println!("Result: {}", result);
+                }
+            },
+            Err(err) => {
+                eprintln!("Error executing script: {}", err);
+                // Exit with error code when a script fails
+                process::exit(1);
+            }
+        }
+    }
+
+    println!("\nAll scripts executed successfully!");
+    Ok(())
+}
+
+/// Recursively collect all .rhai files from a directory
+///
+/// # Arguments
+///
+/// * `dir` - Directory to search
+/// * `files` - Vector to collect files into
+///
+/// # Returns
+///
+/// Result indicating success or failure
+fn collect_rhai_files(dir: &Path, files: &mut Vec<PathBuf>) -> Result<(), Box<dyn Error>> {
+    for entry in fs::read_dir(dir)? {
+        let entry = entry?;
+        let path = entry.path();
+        
+        if path.is_dir() {
+            // Recursively search subdirectories
+            collect_rhai_files(&path, files)?;
+        } else if path.is_file() {
+            // Check if it's a .rhai file
+            if let Some(extension) = path.extension() {
+                if extension == "rhai" {
+                    files.push(path);
+                }
+            }
+        }
+    }
+    
+    Ok(())
+}