fix: open printable Study Load via blob URL to avoid cross-origin document error

content.js

@@ -156,13 +156,18 @@
       if (!included.length) throw new Error('No enrolled courses found.');
       const totalUnits = ISMIStools.sumUnits(included);
       const html = ISMIStools.buildStudyLoadHtml({ header, courses: included, totalUnits });
-      const win = window.open('', '_blank');
+      const blob = new Blob([html], { type: 'text/html' });
+      const url = URL.createObjectURL(blob);
+      const win = window.open(url, '_blank');
       if (!win) {
+        URL.revokeObjectURL(url);
         showToast('Popup blocked — allow popups for this site, then try again.', true);
         return;
       }
-      win.document.write(html);
-      win.document.close();
+      // The blob document runs its own onload → window.print(). Never touch
+      // win.document here: if the new tab navigates cross-origin, accessing it
+      // throws "Permission denied".
+      setTimeout(() => URL.revokeObjectURL(url), 60000);
       showToast('Opened printable Study Load.');
     } catch (err) {
       showToast('Error: ' + ((err && err.message) || err), true);