change to use jinja2 and stop saving file and then reading the data

templates/login.jinja

@@ -0,0 +1,16 @@
+{%set page_title = "Login"%}
+{% extends "base.jinja" %}
+{% block body %}
+<form class="login-box" method="POST" action="/login-and-download">
+    <h2>Coventry University Login</h2>
+
+    <input type="text" name="username" placeholder="Username" required>
+
+    <input type="password" name="password" placeholder="Password" required>
+
+    <button type="submit">Login & Download</button>
+
+    <!-- Optional: server can re-render this with an error message -->
+    {% if error|trim %}<div class="error">{{error}}</div>{% endif %}
+</form>
+{% endblock %}