support serverless environments (#29)

* add --executable-path

* tests

* test vercel

* fixes

cli/src/main.rs

@@ -149,13 +149,23 @@ fn main() {
         }
     };
 
-    if let Err(e) = ensure_daemon(&flags.session, flags.headed) {
-        if flags.json {
-            println!(r#"{{"success":false,"error":"{}"}}"#, e);
-        } else {
-            eprintln!("\x1b[31m✗\x1b[0m {}", e);
+    let daemon_result = match ensure_daemon(&flags.session, flags.headed, flags.executable_path.as_deref()) {
+        Ok(result) => result,
+        Err(e) => {
+            if flags.json {
+                println!(r#"{{"success":false,"error":"{}"}}"#, e);
+            } else {
+                eprintln!("\x1b[31m✗\x1b[0m {}", e);
+            }
+            exit(1);
+        }
+    };
+
+    // Warn if executable_path was specified but daemon was already running
+    if daemon_result.already_running && flags.executable_path.is_some() {
+        if !flags.json {
+            eprintln!("\x1b[33m⚠\x1b[0m --executable-path ignored: daemon already running. Use 'agent-browser close' first to restart with new path.");
         }
-        exit(1);
     }
 
     // If --headed flag is set, send launch command first to switch to headed mode