added standard-theme function

app/utils/helpers.py

@@ -144,3 +144,20 @@ def load_soundboard_config(filename, config_dir, sounds_dir=None):
                 for item in data[key]:
                     item.setdefault('base_path', base_sound_dir)
         return data
+
+
+def read_default_theme(path):
+    try:
+        if not os.path.exists(path):
+            return None
+        with open(path, 'r', encoding='utf-8') as f:
+            val = f.read().strip()
+        return val or None
+    except Exception:
+        return None
+
+
+def write_default_theme(path, filename):
+    os.makedirs(os.path.dirname(path), exist_ok=True)
+    with open(path, 'w', encoding='utf-8') as f:
+        f.write(filename)