feat(ticket): record urges in thread, show urge count in admin, mail admins

- aksrt_ticket gains urge_count / last_urge_time (schema 3.1.0)
- cooldown moves from transient to an atomic conditional UPDATE
- urge inserts a system reply rendered as a centered notice (not quotable)
- admin list badge + info card row for urge count / last time
- new ticket_urge_admin mail event via aksrt_ticket_urged

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/Settings/MailNotifications.php

@@ -26,6 +26,28 @@ final class MailNotifications {
         add_action('aksrt_friend_link_submitted', [self::class, 'friend_link_submitted'], 20, 1);
         add_action('aksrt_user_phone_changed', [self::class, 'phone_changed'], 20, 2);
         add_action('aksrt_user_restriction_changed', [self::class, 'restriction_changed'], 20, 4);
+        add_action('aksrt_ticket_urged', [self::class, 'ticket_urged'], 20, 1);
+    }
+
+    /**
+     * 催单邮件：已指派跟进人时只发给跟进人，否则发给全部管理员（与站内通知同一路由）。
+     *
+     * @param array<string,mixed> $ticket
+     */
+    public static function ticket_urged(array $ticket): void {
+        $vars = [
+            'username' => (string) ($ticket['user_name'] ?? ''),
+            'count' => (int) ($ticket['urge_count'] ?? 0),
+            'ticket_num' => (string) ($ticket['ticket_num'] ?? ''),
+            'title' => (string) ($ticket['title'] ?? ''),
+            'url' => admin_url('users.php?page=aksrt_tickets&id=' . (int) ($ticket['id'] ?? 0)),
+        ];
+        $assignee = get_userdata((int) ($ticket['admin_id'] ?? 0));
+        if ($assignee instanceof \WP_User && is_email($assignee->user_email)) {
+            self::send('ticket_urge_admin', $assignee->user_email, $vars);
+            return;
+        }
+        self::send_admin('ticket_urge_admin', $vars);
     }
 
     public static function restriction_changed(int $user_id, string $type, string $action, string $reason): void {