refactor: 死代码清理 + CDN SRI 加固 + 面包屑组件 + 代码规范文档

- 删除 7 个死模板文件 (products/services/quality/process/projects/customization/rfq)
- 删除 13 个旧图片素材 (jpg/png/webp)
- 新增 CDN SRI 完整性校验 (Bootstrap CSS/JS)
- 新增面包屑导航模板组件
- 新增代码清理方案与代码审查标准文档
- 更新 README.md

inc/inquiry.php

@@ -1,5 +1,13 @@
 <?php
-/** Secure B2B RFQ handling. @package Fragrance_Trade */
+/**
+ * Secure RFQ form handler (deprecated).
+ *
+ * @package Fragrance_Trade
+ * @deprecated 2.1.0 Contact page no longer has a form. This handler remains
+ *             registered but is never triggered. Kept as a security reference
+ *             implementation (nonce + honeypot + rate-limit + header injection
+ *             guard) in case a booking form is re-introduced.
+ */
 
 if ( ! defined( 'ABSPATH' ) ) {
 	exit;