feat(extension): convert popup to persistent side panel

extension/background.js

@@ -145,6 +145,13 @@ async function verifyImageUrl(imageUrl) {
   return result
 }
 
+// ── Side panel ────────────────────────────────────────────────────────────────
+
+// Open the side panel when the toolbar icon is clicked (stays open while browsing)
+chrome.action.onClicked.addListener((tab) => {
+  chrome.sidePanel.open({ windowId: tab.windowId })
+})
+
 // ── Message handler ───────────────────────────────────────────────────────────
 
 chrome.runtime.onMessage.addListener((msg, _sender, sendResponse) => {

extension/manifest.json

@@ -7,9 +7,14 @@
   "permissions": [
     "storage",
     "activeTab",
-    "scripting"
+    "scripting",
+    "sidePanel"
   ],
 
+  "side_panel": {
+    "default_path": "popup.html"
+  },
+
   "host_permissions": [
     "https://www.facebook.com/*",
     "https://facebook.com/*",
@@ -67,7 +72,6 @@
   ],
 
   "action": {
-    "default_popup": "popup.html",
     "default_title": "PhilVerify — Fact Check",
     "default_icon": {
       "16":  "icons/icon16.png",