cleanup callback name and enfore db update

changedetectionio/__init__.py

@@ -1213,12 +1213,13 @@ def changedetection_app(config=None, datastore_o=None):
         flash("{} watches are queued for rechecking.".format(i))
         return redirect(url_for('index', tag=tag))
 
-    @app.route("/toggle-theme", methods=['GET'])
+    @app.route("/toggle-darkmode-state", methods=['GET'])
     @login_required
-    def toggle_theme():
+    def toggle_darkmode_state():
       current_mode = datastore.data['settings']['application'].get('css_dark_mode')
       new_mode = not current_mode
       datastore.data['settings']['application']['css_dark_mode'] = new_mode
+      datastore.needs_write = True
       return ''
 
     @app.route("/form/checkbox-operations", methods=['POST'])

changedetectionio/static/js/toggle-theme.js

@@ -3,7 +3,7 @@
  * Toggles theme between light and dark mode.
  */
 $(document).ready(function () {
-  const url = "/toggle-theme";
+  const url = "/toggle-darkmode-state";
 
   const button = document.getElementsByClassName("toggle-theme")[0];