feat: add card layout tweak with unified post observer

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

content/tweaks/badges.js

@@ -1,8 +1,6 @@
 (function () {
   "use strict";
 
-  let contentObserver = null;
-  let darkModeObserver = null;
   let currentSettings = null;
 
   function applyColorsToContainer(container, settings, subredditName) {
@@ -93,52 +91,6 @@
     });
   }
 
-  function getObserverTarget() {
-    return (
-      document.getElementById("siteTable") ||
-      document.querySelector('.content[role="main"]') ||
-      document.body
-    );
-  }
-
-  function startContentObserver(settings) {
-    if (contentObserver) contentObserver.disconnect();
-
-    const target = getObserverTarget();
-    contentObserver = new MutationObserver(function (mutations) {
-      let hasNewPosts = false;
-      for (const mutation of mutations) {
-        for (const node of mutation.addedNodes) {
-          if (node.nodeType === Node.ELEMENT_NODE) {
-            if (node.matches && node.matches("div.thing.link")) {
-              hasNewPosts = true;
-            } else if (node.querySelector && node.querySelector("div.thing.link")) {
-              hasNewPosts = true;
-            }
-          }
-        }
-      }
-      if (hasNewPosts) processPosts(currentSettings);
-    });
-
-    contentObserver.observe(target, { childList: true, subtree: true });
-  }
-
-  function startDarkModeObserver() {
-    if (darkModeObserver) darkModeObserver.disconnect();
-
-    darkModeObserver = new MutationObserver(function () {
-      if (currentSettings && currentSettings.darkMode === "auto") {
-        updateColors(currentSettings);
-      }
-    });
-
-    darkModeObserver.observe(document.body, {
-      attributes: true,
-      attributeFilter: ["class"],
-    });
-  }
-
   function updateColors(settings) {
     currentSettings = settings;
     const containers = document.querySelectorAll(".reddit-tweaks-badges");
@@ -155,8 +107,6 @@
   function apply(settings) {
     currentSettings = settings;
     processPosts(settings);
-    startContentObserver(settings);
-    startDarkModeObserver();
   }
 
   window.RedditTweaks = window.RedditTweaks || {};
@@ -165,5 +115,6 @@
     updateColors: updateColors,
     isDarkMode: window.RedditTweaks.isDarkMode,
     getColorPrefix: window.RedditTweaks.getColorPrefix,
+    processNewPosts: processPosts,
   };
 })();