chore: remove content script and update manifest for service worker

background.js

@@ -0,0 +1,10 @@
+chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
+    if (changeInfo.status === "complete" && /^https?:/.test(tab.url)) {
+        chrome.scripting.executeScript({
+            target: { tabId },
+            files: ["main.js"]
+        }).catch(err => {
+            console.warn("Injection failed:", err);
+        });
+    }
+});

manifest.json

@@ -5,23 +5,19 @@
   "description": "Highlight text on web pages",
   "default_locale": "en",
   "permissions": [
+    "scripting",
     "storage"
   ],
+  "host_permissions": [
+    "<all_urls>"
+  ],
   "action": {
     "default_popup": "popup/popup.html",
     "default_icon": "icons/icon128.png"
   },
-  "content_scripts": [
-    {
-      "matches": [
-        "<all_urls>"
-      ],
-      "js": [
-        "content.js"
-      ],
-      "run_at": "document_idle"
-    }
-  ],
+  "background": {
+    "service_worker": "background.js"
+  },
   "icons": {
     "48": "icons/icon48.png",
     "128": "icons/icon128.png"