Add MCP server to AST tool

Integrates the MCP server functionality into the AST tool binary. This
allows the tool to act as a server for LLM integration, enabling
communication over stdio. The server can list available bindings and
execute scripts.

src/bin/ast.rs

@@ -39,10 +39,22 @@ struct Cli {
     /// Disable optimization
     #[arg(long)]
     no_opt: bool,
+
+    /// Start MCP server (stdio transport, for LLM integration)
+    #[arg(long)]
+    mcp: bool,
 }
 
 fn main() {
     let cli = Cli::parse();
+
+    if cli.mcp {
+        if let Err(e) = myc::ast::mcp_server::run() {
+            eprintln!("MCP server error: {}", e);
+            std::process::exit(1);
+        }
+        return;
+    }
     let mut env = Environment::new();
     env.optimization = !cli.no_opt;