feat: add secure invitation and reset links

templates/admin.html

@@ -22,6 +22,17 @@
   </form>
 </section>
 
+<section class="mt-6 rounded-xl border border-line bg-white p-5 shadow-panel">
+  <h2 class="font-extrabold">邀请注册</h2>
+  <p class="mt-1 text-sm text-textSub">即使关闭自助注册，也可向指定邮箱发送一次性注册链接。</p>
+  <form method="post" action="{{ url_for('main.admin_send_registration_invitation') }}" class="mt-4 flex flex-col gap-2 sm:flex-row" novalidate>
+    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
+    <label class="sr-only" for="inviteEmail">受邀邮箱</label>
+    <input id="inviteEmail" name="email" type="email" required autocomplete="email" class="min-w-0 flex-1 rounded-lg border border-line px-3 py-2 text-sm" placeholder="受邀人的邮箱地址">
+    <button class="ui-btn ui-btn-sm ui-btn-primary shrink-0">发送注册链接</button>
+  </form>
+</section>
+
 <section class="mt-6 rounded-xl border border-line bg-white p-5 shadow-panel">
   <div class="flex flex-col gap-4 sm:flex-row sm:items-end sm:justify-between">
     <div>