feat: handle Garmin MFA and activity retries

app/web/templates/fragments/mfa_form.html

@@ -0,0 +1,5 @@
+<form method="post" action="/users/{{ user.id }}/garmin-mfa">
+    <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+    <label>Garmin MFA code: <input type="text" name="code" maxlength="20" required></label>
+    <button type="submit">Submit code</button>
+</form>

app/web/templates/users/detail.html

@@ -28,4 +28,26 @@
     <dt>Updated at</dt>
     <dd>{{ user.updated_at }}</dd>
 </dl>
+
+{% if user.action_reason == "garmin_mfa_required" %}
+<h2>Garmin MFA required</h2>
+{% include "fragments/mfa_form.html" %}
+{% endif %}
+
+<h2>Activities</h2>
+<ul>
+    {% for activity in activities %}
+    <li>
+        {{ activity.activity_name }} &mdash; {{ activity.status.value }}
+        {% if activity.status.value == "failed" and activity.retryable %}
+        <form method="post" action="/activities/{{ activity.id }}/retry" style="display:inline">
+            <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+            <button type="submit">Retry</button>
+        </form>
+        {% endif %}
+    </li>
+    {% else %}
+    <li>No pending activities.</li>
+    {% endfor %}
+</ul>
 {% endblock %}