fix(ui): system theming for charts (#5740)

resources/views/layouts/base.blade.php

@@ -83,6 +83,9 @@
 
             function checkTheme() {
                 theme = localStorage.theme
+                if (theme == 'system') {
+                    theme = window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light'
+                }
                 if (theme == 'dark') {
                     baseColor = '#FCD452'
                     textColor = '#ffffff'