feat: 初始版本，圆角主题与首次管理员引导

app/templates/posts/create.html

@@ -0,0 +1,19 @@
+{% extends 'base.html' %}
+{% block title %}发布作品{% endblock %}
+{% block content %}
+<h3 class="mb-3">发布作品</h3>
+<form class="card p-3" method="post" enctype="multipart/form-data">
+  <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+  <div class="mb-3"><label class="form-label">标题</label><input class="form-control" name="title" required></div>
+  <div class="mb-3"><label class="form-label">介绍</label><textarea class="form-control" name="description"></textarea></div>
+  <div class="mb-3"><label class="form-label">可见性</label>
+    <select class="form-select" name="visibility">
+      <option value="public">公开（需审核）</option>
+      <option value="followers">仅关注者</option>
+      <option value="private">仅自己</option>
+    </select>
+  </div>
+  <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-brand" type="submit">提交</button>
+</form>
+{% endblock %}