feat: support http update checks

src/app/main_window.py

@@ -149,15 +149,17 @@ class MainWindow(QMainWindow):
         return bar
 
     def _start_update_check(self):
-        """Check the configured LAN source for a newer version, off the UI thread."""
+        """Check the configured update source for a newer version, off the UI thread."""
         source = self._config.get("update_source", "")
         if not source:
             return
+        user = self._config.get("update_user", "")
+        password = self._config.get("update_pass", "")
         self._update_found.connect(self._on_update_found)
 
         def worker():
             try:
-                info = check_for_update(source, APP_VERSION)
+                info = check_for_update(source, APP_VERSION, user, password)
             except Exception:                      # never let the thread crash startup
                 logger.exception("Update check failed")
                 return
@@ -191,6 +193,9 @@ class MainWindow(QMainWindow):
             self._config.get("update_source", ""),
         ]
         for path in candidates:
+            if path and path.lower().startswith(("http://", "https://")):
+                if QDesktopServices.openUrl(QUrl(path)):
+                    return
             if not path or not Path(path).exists():
                 continue
             try: