Summary report UI improvements and JS preview logic

templates/upload.html

@@ -9,7 +9,7 @@
 {% block content %}
 <div class="container">
     <h2>Upload Income Tax Documents</h2>
-    <form id="income_tax_documents" method="POST" enctype="multipart/form-data">
+    <form id="documents" method="POST" enctype="multipart/form-data">
         <label>Year:</label>
         <select id="year" name="year" required></select>
         <div id="yearError" style="color: red; display: none; margin-bottom: 10px;"></div>