feat: add dark mode styling for combat values

scss/components/actor/_combat_value.scss

@@ -71,3 +71,13 @@
     flex: 1 1 4em;
   }
 }
+
+// Dark mode filter for combat value backgrounds when in dark theme
+.theme-dark .ds4-combat-value__value {
+  filter: invert(1);
+
+  // Counter-invert the text to keep it normal
+  .ds4-combat-value__text {
+    filter: invert(1);
+  }
+}