refactor(kefin-tweaks): use the standard ListItem/disabledByAdmin pattern

Rebuild the KefinTweaks toggle on ListGroup + ListItem like the other
plugin settings: drop the bespoke card, the red label, the custom switch
colours, and the `t("Watchlist On")`/`t("Watchlist Off")` literal-as-key
strings. The admin lock now shows via the ListItem subtitle instead of
wrapping the whole screen in DisabledSetting.

app/(auth)/(tabs)/(home)/settings/plugins/kefinTweaks/page.tsx

@@ -1,11 +1,8 @@
-import { ScrollView } from "react-native";
+import { ScrollView, View } from "react-native";
 import { useSafeAreaInsets } from "react-native-safe-area-context";
-import DisabledSetting from "@/components/settings/DisabledSetting";
 import { KefinTweaksSettings } from "@/components/settings/KefinTweaks";
-import { useSettings } from "@/utils/atoms/settings";
 
 export default function KefinTweaksPage() {
-  const { pluginSettings } = useSettings();
   const insets = useSafeAreaInsets();
 
   return (
@@ -16,12 +13,9 @@ export default function KefinTweaksPage() {
         paddingRight: insets.right,
       }}
     >
-      <DisabledSetting
-        disabled={pluginSettings?.useKefinTweaks?.locked === true}
-        className='p-4'
-      >
+      <View className='px-4'>
         <KefinTweaksSettings />
-      </DisabledSetting>
+      </View>
     </ScrollView>
   );
 }