refactor: extract isDarkMode/getColorPrefix to settings.js as shared utilities

Co-authored-by: Cursor <cursoragent@cursor.com>

content/tweaks/badges.js

@@ -5,20 +5,10 @@
   let darkModeObserver = null;
   let currentSettings = null;
 
-  function isDarkMode(settings) {
-    if (settings.darkMode === "light") return false;
-    if (settings.darkMode === "dark") return true;
-    return document.body.classList.contains("res-nightmode");
-  }
-
-  function getColorPrefix(settings) {
-    return isDarkMode(settings) ? "dark" : "light";
-  }
-
   function applyColorsToContainer(container, settings, subredditName) {
-    const prefix = getColorPrefix(settings);
+    const prefix = window.RedditTweaks.getColorPrefix(settings);
 
-    if (isDarkMode(settings)) {
+    if (window.RedditTweaks.isDarkMode(settings)) {
       container.classList.add("rt-dark");
     } else {
       container.classList.remove("rt-dark");
@@ -173,7 +163,7 @@
   window.RedditTweaks.badgeTweak = {
     apply: apply,
     updateColors: updateColors,
-    isDarkMode: isDarkMode,
-    getColorPrefix: getColorPrefix,
+    isDarkMode: window.RedditTweaks.isDarkMode,
+    getColorPrefix: window.RedditTweaks.getColorPrefix,
   };
 })();