feat: 初始版本，圆角主题与首次管理员引导

app/templates/activities/detail.html

@@ -0,0 +1,7 @@
+{% extends 'base.html' %}
+{% block title %}活动详情{% endblock %}
+{% block content %}
+<h3>{{ activity.title }}</h3>
+<p>{{ activity.description }}</p>
+<a class="btn btn-primary" href="{{ url_for('activities.submit', act_id=activity.id) }}">投稿</a>
+{% endblock %}

app/templates/activities/list.html

@@ -0,0 +1,10 @@
+{% extends 'base.html' %}
+{% block title %}活动{% endblock %}
+{% block content %}
+<h3>活动</h3>
+<ul>
+  {% for a in activities %}
+  <li><a href="{{ url_for('activities.detail', act_id=a.id) }}">{{ a.title }}</a></li>
+  {% endfor %}
+</ul>
+{% endblock %}

app/templates/activities/submit.html

@@ -0,0 +1,10 @@
+{% extends 'base.html' %}
+{% block title %}投稿{% endblock %}
+{% block content %}
+<h3>向 {{ activity.title }} 投稿</h3>
+<form method="post" enctype="multipart/form-data">
+  <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+  <div class="mb-3"><label class="form-label">图片</label><input class="form-control" name="images" type="file" accept="image/*" multiple required></div>
+  <button class="btn btn-primary" type="submit">提交</button>
+</form>
+{% endblock %}