fix: Windows auto-connect profiling (#835) (#840)

* fix: Windows auto-connect profiling (#835)

Fix three interrelated bugs causing `--auto-connect` to fail on Windows,
plus a UX issue where auto-connect hijacked existing tabs:

1. Stale DevToolsActivePort — add TCP port liveness check before returning
   M144+ WebSocket URL; remove stale files when port is dead.

2. Missing Windows error codes — add os error 10061 (WSAECONNREFUSED) and
   10054 (WSAECONNRESET) to is_transient_error() so daemon startup races
   are retried on Windows.

3. --auto-connect not propagated to daemon — add auto_connect to
   DaemonOptions, set AGENT_BROWSER_AUTO_CONNECT env var via
   apply_daemon_env(), and guard the headed launch block so it doesn't
   send a second launch that overrides the auto-connect.

4. Auto-connect opens a fresh tab — after connecting to an existing
   Chrome, create a new about:blank tab and bring it to front so
   navigations don't hijack the user's existing tabs.

Made-with: Cursor

* fix: address review feedback — cargo fmt, shared helper, Windows tests

- Run cargo fmt on is_port_reachable() formatting
- Extract duplicated auto-connect-with-fresh-tab logic into
  connect_auto_with_fresh_tab() helper used by both handle_launch()
  and auto_launch()
- Add unit tests for Windows WSAECONNREFUSED (os error 10061) and
  WSAECONNRESET (os error 10054) in is_transient_error()

---------

Co-authored-by: ctate <366502+ctate@users.noreply.github.com>

cli/src/native/actions.rs

@@ -792,6 +792,19 @@ pub async fn execute_command(cmd: &Value, state: &mut DaemonState) -> Value {
 // Auto-launch
 // ---------------------------------------------------------------------------
 
+/// Connect to a running Chrome via auto-discovery and open a fresh tab so
+/// subsequent navigations don't hijack the user's existing tabs.
+async fn connect_auto_with_fresh_tab() -> Result<BrowserManager, String> {
+    let mut mgr = BrowserManager::connect_auto().await?;
+    mgr.tab_new(None).await?;
+    let session_id = mgr.active_session_id()?.to_string();
+    let _ = mgr
+        .client
+        .send_command("Page.bringToFront", None, Some(&session_id))
+        .await;
+    Ok(mgr)
+}
+
 async fn auto_launch(state: &mut DaemonState) -> Result<(), String> {
     let options = launch_options_from_env();
     let engine = env::var("AGENT_BROWSER_ENGINE").ok();
@@ -806,8 +819,7 @@ async fn auto_launch(state: &mut DaemonState) -> Result<(), String> {
     }
 
     if env::var("AGENT_BROWSER_AUTO_CONNECT").is_ok() {
-        let mgr = BrowserManager::connect_auto().await?;
-        state.browser = Some(mgr);
+        state.browser = Some(connect_auto_with_fresh_tab().await?);
         state.subscribe_to_browser_events();
         state.update_stream_client().await;
         try_auto_restore_state(state).await;
@@ -971,7 +983,7 @@ async fn handle_launch(cmd: &Value, state: &mut DaemonState) -> Result<Value, St
     }
 
     if auto_connect {
-        state.browser = Some(BrowserManager::connect_auto().await?);
+        state.browser = Some(connect_auto_with_fresh_tab().await?);
         state.subscribe_to_browser_events();
         state.update_stream_client().await;
         return Ok(json!({ "launched": true }));

cli/src/native/cdp/chrome.rs

@@ -453,9 +453,17 @@ pub async fn auto_connect_cdp() -> Result<String, String> {
             if let Ok(ws_url) = discover_cdp_url("127.0.0.1", port).await {
                 return Ok(ws_url);
             }
-            // M144+: direct WebSocket
-            let ws_url = format!("ws://127.0.0.1:{}{}", port, ws_path);
-            return Ok(ws_url);
+            // M144+: direct WebSocket — verify the port is actually listening
+            // before returning, otherwise a stale DevToolsActivePort file
+            // (left behind after Chrome exits/crashes) produces a confusing
+            // "connection refused" error instead of falling through.
+            if is_port_reachable(port) {
+                let ws_url = format!("ws://127.0.0.1:{}{}", port, ws_path);
+                return Ok(ws_url);
+            }
+            // Port is dead — remove the stale file so future runs skip it.
+            let stale = dir.join("DevToolsActivePort");
+            let _ = std::fs::remove_file(&stale);
         }
     }
 
@@ -469,6 +477,12 @@ pub async fn auto_connect_cdp() -> Result<String, String> {
     Err("No running Chrome instance found. Launch Chrome with --remote-debugging-port or use --cdp.".to_string())
 }
 
+fn is_port_reachable(port: u16) -> bool {
+    use std::net::TcpStream;
+    let addr = format!("127.0.0.1:{}", port);
+    TcpStream::connect_timeout(&addr.parse().unwrap(), Duration::from_millis(500)).is_ok()
+}
+
 fn get_chrome_user_data_dirs() -> Vec<PathBuf> {
     let mut dirs = Vec::new();