feat: restore direct PDF download via background; drop printdoc

manifest.json

@@ -1,14 +1,17 @@
 {
   "manifest_version": 3,
   "name": "ISMIS Helper",
-  "version": "1.1.0",
-  "description": "Auto-login, auto-accept privacy policy, and printable Study Load for the USC ISMIS portal.",
-  "permissions": ["storage"],
+  "version": "1.2.0",
+  "description": "Auto-login, auto-accept privacy policy, and Study Load PDF for the USC ISMIS portal.",
+  "permissions": ["storage", "downloads"],
   "host_permissions": ["https://ismis.usc.edu.ph/*"],
+  "background": {
+    "scripts": ["libs/pdf-lib.min.js", "pdf.js", "background.js"]
+  },
   "content_scripts": [
     {
       "matches": ["https://ismis.usc.edu.ph/*"],
-      "js": ["parsers.js", "printdoc.js", "content.js"],
+      "js": ["parsers.js", "content.js"],
       "run_at": "document_idle"
     }
   ],