Harden Lildra layout and refresh branding

manifest.json

@@ -2,7 +2,7 @@
   "manifest_version": 3,
   "name": "Lildra",
   "version": "0.2.3",
-  "description": "A minimal Canvas and QLearn page view with hidden navigation, centred content, a compact fixed page title and version label.",
+  "description": "A distraction-free reading layout for Canvas and QLearn lesson pages.",
   "permissions": [
     "activeTab",
     "scripting"
@@ -11,7 +11,13 @@
     "service_worker": "background.js"
   },
   "action": {
-    "default_title": "Toggle Lildra"
+    "default_title": "Toggle Lildra",
+    "default_icon": {
+      "16": "icons/LildraLogo16.png",
+      "32": "icons/LildraLogo32.png",
+      "48": "icons/LildraLogo48.png",
+      "128": "icons/LildraLogo128.png"
+    }
   },
   "commands": {
     "toggle-lildra": {
@@ -23,9 +29,9 @@
     }
   },
   "icons": {
-    "16": "icons/icon16.png",
-    "32": "icons/icon32.png",
-    "48": "icons/icon48.png",
-    "128": "icons/icon128.png"
+    "16": "icons/LildraLogo16.png",
+    "32": "icons/LildraLogo32.png",
+    "48": "icons/LildraLogo48.png",
+    "128": "icons/LildraLogo128.png"
   }
-}
+}