feat(identity): tip QR upload, metrics engine, comment moderate caps

Close identity 1:1 gaps after p1: user-center weixin/alipay tip QR
upload+save, AKSRT_User_Metrics counters for medal get_type and level
XP bridges, forum/revenue/signin hooks, comment moderate via user_caps,
and clearer free-task deep links/status CTAs.

inc/helpers/aksrt-user-center.php

@@ -91,6 +91,32 @@ if (!function_exists('aksrt_save_user_center_profile')) {
 		}
 
 		update_user_meta($user_id, 'aksrt_user_contacts', aksrt_normalize_user_contacts($input['contacts'] ?? []));
+
+		// Tip QR images (attachment id or URL). Empty clears.
+		if (array_key_exists('rewards_weixin', $input) || array_key_exists('rewards_alipay', $input)) {
+			foreach (['rewards_weixin' => 'aksrt_rewards_weixin', 'rewards_alipay' => 'aksrt_rewards_alipay'] as $field => $meta) {
+				if (!array_key_exists($field, $input)) {
+					continue;
+				}
+				$raw = is_string($input[$field]) ? trim(wp_unslash($input[$field])) : '';
+				if ($raw === '' || $raw === '0') {
+					delete_user_meta($user_id, $meta);
+					continue;
+				}
+				if (ctype_digit($raw)) {
+					$att = (int) $raw;
+					if ($att > 0 && wp_attachment_is_image($att)) {
+						update_user_meta($user_id, $meta, $att);
+					}
+					continue;
+				}
+				$url = esc_url_raw($raw);
+				if ($url !== '') {
+					update_user_meta($user_id, $meta, $url);
+				}
+			}
+		}
+
 		return true;
 	}
 }