feat(v1.4.0): exports + smart year level + progress + encrypted passwords

v1.4.0: CSV/Excel/JSON/NextUp exports, units-first smart year standing, live export progress bar, AES-GCM at-rest password encryption.

popup.html

@@ -36,10 +36,18 @@
     <h2>PDF Settings</h2>
     <label class="row"><input type="checkbox" id="truncateToggle"> Truncate long course descriptions (official PDF style)</label>
     <label class="row"><input type="checkbox" id="showYearToggle"> Show Year Level on the PDF</label>
+    <div class="row">Year Level mode:
+      <select id="yearMode">
+        <option value="auto">Auto (recommended)</option>
+        <option value="custom">Use custom value</option>
+        <option value="off">Profile value only</option>
+      </select>
+    </div>
     <label class="row">Custom Year Level (optional):
       <input type="text" id="customYear" placeholder="e.g. 3">
     </label>
-    <p class="hint">Leave blank to use the scraped value (auto-adjusted in Summer).</p>
+    <p class="hint">Auto derives the standing of the semester being printed (from
+      View Grades, or remaining units). Profile value only disables derivation.</p>
   </section>
 
   <script src="popup.js"></script>