Exit fast on Velopack hook args; name ZIP artifact win64-portable

Velopack runs the app with --veloapp-install/-updated/-uninstall during
those operations; without fast-exit handling the full GUI booted
mid-install (also clobbering config via the first-run setup flow) and
the installer reported hook errors. The post-install launch has no hook
args and still starts the app normally.

mediahive/winmain.py

@@ -978,6 +978,10 @@ def _show_fatal_error(exc: BaseException) -> None:
 
 def gui_main() -> None:
     """Run the GUI, rendering fatal exceptions as a TraceRite HTML window."""
+    # Velopack runs the app with --veloapp-* hook arguments during install,
+    # update, and uninstall; these must exit fast instead of starting the GUI.
+    if any(arg.startswith("--veloapp-") for arg in sys.argv[1:]):
+        return
     try:
         winmain()
     except Exception as exc:

scripts/guibuild.py

@@ -338,6 +338,9 @@ def create_zip(version: str) -> Path:
         raise FileNotFoundError(f"Distribution folder not found: {dist_folder}")
 
     zip_name = f"MediaHive-{version}-{_platform_zip_suffix()}.zip"
+    if sys.platform == "win32":
+        # Distinguish from the Velopack installer (MediaHive-*-win64-setup.exe)
+        zip_name = zip_name.replace("-win64.zip", "-win64-portable.zip")
     zip_path = repo_root / "build" / zip_name
     zip_path.parent.mkdir(parents=True, exist_ok=True)