fix windows desktop bridge startup (#1196)

packages/server/src/services/hermes/agent-bridge/hermes_bridge.py

@@ -71,6 +71,40 @@ def _hidden_subprocess_kwargs() -> dict[str, int]:
     return {"creationflags": getattr(subprocess, "CREATE_NO_WINDOW", 0)}
 
 
+def _install_windows_hidden_subprocess_defaults() -> None:
+    """Hide console windows for subprocesses launched inside desktop bridge runs.
+
+    The desktop bridge itself must keep stdout/stderr pipes for readiness and
+    worker handshakes, so it runs under python.exe. On Windows that means any
+    nested console executable, including git.exe from context expansion, can
+    flash a window unless the child process is created with CREATE_NO_WINDOW.
+    """
+    if os.name != "nt":
+        return
+    if os.environ.get("HERMES_DESKTOP", "").strip().lower() != "true":
+        return
+    if getattr(subprocess, "_hermes_hidden_defaults_installed", False):
+        return
+
+    original_popen = subprocess.Popen
+    create_no_window = getattr(subprocess, "CREATE_NO_WINDOW", 0) or 0x08000000
+
+    class HiddenPopen(original_popen):  # type: ignore[misc, valid-type]
+        def __init__(self, *args: Any, **kwargs: Any) -> None:
+            flags = kwargs.get("creationflags", 0) or 0
+            try:
+                kwargs["creationflags"] = int(flags) | create_no_window
+            except Exception:
+                kwargs["creationflags"] = create_no_window
+            super().__init__(*args, **kwargs)
+
+    subprocess.Popen = HiddenPopen  # type: ignore[assignment]
+    subprocess._hermes_hidden_defaults_installed = True  # type: ignore[attr-defined]
+
+
+_install_windows_hidden_subprocess_defaults()
+
+
 def _process_exists(pid: int) -> bool:
     if pid <= 0:
         return False