feat(connect): make auto-connect to user's Chrome the default behavior

- Auto-connect is now ON by default (was opt-in via --auto-connect)
- Added --launch/--new flags to explicitly start a fresh browser
- CI environments (CI env var) automatically use --launch mode
- Friendly error message with platform-specific Chrome relaunch guide
- Mentions Chrome 144+ runtime CDP toggle (chrome://inspect)
- --cdp and --provider flags implicitly disable auto-connect
- AGENT_BROWSER_NO_AUTO_CONNECT=1 to disable, AGENT_BROWSER_FORCE_LAUNCH=1 to force

Track 3 of native-stealth migration.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cli/src/flags.rs

@@ -308,6 +308,7 @@ pub struct Flags {
     pub allow_file_access: bool,
     pub device: Option<String>,
     pub auto_connect: bool,
+    pub force_launch: bool,
     pub session_name: Option<String>,
     pub annotate: bool,
     pub color_scheme: Option<String>,
@@ -443,8 +444,11 @@ pub fn parse_flags(args: &[String]) -> Flags {
         allow_file_access: env_var_is_truthy("AGENT_BROWSER_ALLOW_FILE_ACCESS")
             || config.allow_file_access.unwrap_or(false),
         device: env::var("AGENT_BROWSER_IOS_DEVICE").ok().or(config.device),
-        auto_connect: env_var_is_truthy("AGENT_BROWSER_AUTO_CONNECT")
-            || config.auto_connect.unwrap_or(false),
+        auto_connect: !env_var_is_truthy("AGENT_BROWSER_NO_AUTO_CONNECT")
+            && (env_var_is_truthy("AGENT_BROWSER_AUTO_CONNECT")
+                || config.auto_connect.unwrap_or(true)),
+        force_launch: env_var_is_truthy("AGENT_BROWSER_FORCE_LAUNCH")
+            || env::var("CI").is_ok(),
         session_name: env::var("AGENT_BROWSER_SESSION_NAME")
             .ok()
             .or(config.session_name),
@@ -682,10 +686,17 @@ pub fn parse_flags(args: &[String]) -> Flags {
             "--auto-connect" => {
                 let (val, consumed) = parse_bool_arg(args, i);
                 flags.auto_connect = val;
+                if !val {
+                    flags.force_launch = true;
+                }
                 if consumed {
                     i += 1;
                 }
             }
+            "--launch" | "--new" => {
+                flags.force_launch = true;
+                flags.auto_connect = false;
+            }
             "--session-name" => {
                 if let Some(s) = args.get(i + 1) {
                     flags.session_name = Some(s.clone());
@@ -842,6 +853,8 @@ pub fn clean_args(args: &[String]) -> Vec<String> {
         "--ignore-https-errors",
         "--allow-file-access",
         "--auto-connect",
+        "--launch",
+        "--new",
         "--annotate",
         "--content-boundaries",
         "--confirm-interactive",