fix(cli): foreground the WebUI browser

nanobot/cli/gateway_runtime.py

@@ -23,6 +23,7 @@ from nanobot.cli.webui_support import (
     _gateway_health_bind_note,
     _gateway_health_url,
     _host_for_local_browser,
+    _launch_browser,
     _prepare_webui_bundle_for_gateway,
     _print_foreground_port_conflict,
     _tcp_endpoint_reachable,
@@ -864,7 +865,6 @@ def _run_gateway(
         """Wait for the gateway to bind, then point the user's browser at the webui."""
         if not open_browser_url:
             return
-        import webbrowser
         from urllib.parse import urlparse
 
         # Channels start asynchronously. When the caller supplies a backend
@@ -896,8 +896,10 @@ def _run_gateway(
                 await asyncio.sleep(0.1)
         display_url = _webui_display_url(open_browser_url)
         try:
-            webbrowser.open(open_browser_url)
-            console.print(f"[green]✓[/green] Opened browser at {display_url}")
+            if _launch_browser(open_browser_url):
+                console.print(f"[green]✓[/green] Opened browser at {display_url}")
+            else:
+                console.print(f"[yellow]Could not open browser; visit {display_url}[/yellow]")
         except Exception as e:
             console.print(f"[yellow]Could not open browser ({e}); visit {display_url}[/yellow]")
 

nanobot/cli/webui_support.py

@@ -1,7 +1,9 @@
 """Shared WebUI setup, URL, health, and browser helpers."""
 
+import subprocess
 import sys
 import time
+import webbrowser
 from collections.abc import Callable
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
@@ -40,6 +42,7 @@ __all__ = [
     "_gateway_instance_command",
     "_host_for_local_browser",
     "_load_webui_setup_config",
+    "_launch_browser",
     "_open_webui_browser",
     "_prepare_webui_bundle_for_gateway",
     "_print_foreground_port_conflict",
@@ -60,6 +63,20 @@ __all__ = [
 console = Console()
 
 
+def _launch_browser(url: str) -> bool:
+    """Open *url* and request a foreground browser window."""
+    if sys.platform == "darwin":
+        result = subprocess.run(
+            ["open", url],
+            stdin=subprocess.DEVNULL,
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+            check=False,
+        )
+        return result.returncode == 0
+    return bool(webbrowser.open(url, new=2, autoraise=True))
+
+
 def _confirm_webui_action(message: str, *, yes: bool) -> None:
     """Confirm a WebUI first-run mutation or fail clearly in non-interactive shells."""
     if yes:
@@ -419,14 +436,14 @@ def _print_foreground_port_conflict(
 
 def _open_webui_browser(url: str, *, wait: bool = True) -> None:
     """Open the WebUI in the user's default browser, with a copyable fallback."""
-    import webbrowser
-
     if wait:
         _wait_for_webui(url)
     display_url = _webui_display_url(url)
     try:
-        webbrowser.open(url)
-        console.print(f"[green]✓[/green] Opened WebUI: [cyan]{display_url}[/cyan]")
+        if _launch_browser(url):
+            console.print(f"[green]✓[/green] Opened WebUI: [cyan]{display_url}[/cyan]")
+        else:
+            console.print(f"[yellow]Could not open browser; visit {display_url}[/yellow]")
     except Exception as exc:
         console.print(f"[yellow]Could not open browser ({exc}); visit {display_url}[/yellow]")