fix(ui): adapt native form controls to dark mode via color-scheme

frontend/src/components/common/DateRangePicker.vue

@@ -405,7 +405,7 @@ onUnmounted(() => {
 }
 
 .dark .date-picker-input::-webkit-calendar-picker-indicator {
-  filter: invert(0.7);
+  filter: none;
 }
 
 .date-picker-separator {

frontend/src/style.css

@@ -9,6 +9,11 @@
 
   html {
     @apply scroll-smooth antialiased;
+    color-scheme: light;
+  }
+
+  .dark {
+    color-scheme: dark;
   }
 
   body {