feat: 邮件系统优化和垃圾评论通知

- 移除所有邮件模板中的 emoji，表述正式化
- 为所有用户邮件添加退订功能支持
- 新增垃圾评论通知邮件模板（spam_notify）
- 检测到垃圾评论时自动发送邮件给评论者
- 邮件包含识别理由、AI 模型、服务提供商、识别码等信息
- 提供查询识别详情和退订链接

email-templates/spam-notify.php

@@ -0,0 +1,74 @@
+<?php
+/**
+ * Argon 垃圾评论通知邮件
+ * 
+ * 当评论被 AI 识别为垃圾评论时发送给评论者
+ */
+
+if (!defined('ABSPATH')) {
+    exit;
+}
+
+/**
+ * 发送垃圾评论通知邮件给评论者
+ * 
+ * @param WP_Comment $comment 评论对象
+ * @param array $detection_result AI 检测结果
+ * @param string $detection_code 识别码
+ * @return bool 发送是否成功
+ */
+function argon_send_spam_notify_email($comment, $detection_result, $detection_code) {
+    // 检查评论者是否留了邮箱
+    if (empty($comment->comment_author_email)) {
+        return false;
+    }
+    
+    // 获取文章信息
+    $post = get_post($comment->comment_post_ID);
+    if (!$post) {
+        return false;
+    }
+    
+    // 获取 AI 配置信息
+    $provider = get_option('argon_ai_summary_provider', 'openai');
+    $model = get_option('argon_ai_summary_model', '');
+    
+    $provider_names = [
+        'openai' => 'OpenAI',
+        'anthropic' => 'Anthropic',
+        'deepseek' => 'DeepSeek',
+        'qianwen' => '通义千问',
+        'wenxin' => '文心一言',
+        'doubao' => '豆包',
+        'kimi' => 'Kimi',
+        'zhipu' => '智谱',
+        'siliconflow' => 'SiliconFlow'
+    ];
+    
+    $provider_display = isset($provider_names[$provider]) ? $provider_names[$provider] : $provider;
+    
+    // 生成退订链接（使用通用的邮件退订机制）
+    $unsubscribe_token = md5($comment->comment_author_email . wp_salt());
+    $unsubscribe_url = add_query_arg([
+        'action' => 'unsubscribe_spam_notify',
+        'email' => urlencode($comment->comment_author_email),
+        'token' => $unsubscribe_token
+    ], home_url());
+    
+    // 准备模板变量
+    $vars = array(
+        'commenter_name' => $comment->comment_author,
+        'post_title' => $post->post_title,
+        'post_url' => get_permalink($post->ID),
+        'comment_content' => $comment->comment_content,
+        'ai_spam_reason' => isset($detection_result['reason']) ? $detection_result['reason'] : '',
+        'ai_model' => $model,
+        'ai_provider' => $provider_display,
+        'ai_detection_code' => $detection_code,
+        'query_url' => home_url('/ai-query?code=' . $detection_code),
+        'unsubscribe_url' => $unsubscribe_url,
+    );
+    
+    // 发送邮件
+    return argon_send_email($comment->comment_author_email, 'spam_notify', $vars);
+}