refactor(headless): default to single-run mode with --loop flag for continuous execution

src/headless.rs

@@ -13,7 +13,8 @@ pub fn run(config_or_task: &str, cwd_override: Option<&str>, name_override: Opti
     create_state_dir();
 
     let args: Vec<String> = std::env::args().collect();
-    let once = args.iter().any(|a| a == "--once");
+    let loop_mode = args.iter().any(|a| a == "--loop");
+    let once = !loop_mode;
 
     let is_multi = config_or_task.ends_with(".json") || std::path::Path::new(config_or_task).is_dir();
     let (configs, interval) = if is_multi {
@@ -149,7 +150,7 @@ pub fn run(config_or_task: &str, cwd_override: Option<&str>, name_override: Opti
 pub fn run_preset(preset_name: &str) -> Result<(), String> {
     let configs = config::preset(preset_name)
         .ok_or_else(|| format!("unknown preset: {preset_name}"))?;
-    let once = std::env::args().any(|a| a == "--once");
+    let once = !std::env::args().any(|a| a == "--loop");
     if once {
         execute_once(configs)
     } else {

src/main.rs

@@ -143,6 +143,7 @@ fn print_help() {
     println!("  aishell run <task>          Run single agent");
     println!("  aishell run -p <preset>     Preset: daily, review, improve, report");
     println!("  aishell run -f <config>     Custom config file");
+    println!("    --loop                    Loop mode (default: run once)");
     println!("  aishell plan -p <preset>    Preview agent config without running");
     println!("  aishell commit              Git commit with AI-suggested message");
     println!("  aishell status [-v]         Show agent status");