fix(docs): remove trailing slash from theme links in migration guide

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: HeJiaYue520

apps/docs/en/guide/migration-v2.md

@@ -678,7 +678,7 @@ A: `XSender` has minor API changes — mainly the rename, plus new props like `v
 
 ### Q: How do I set up dark mode in VitePress?
 
-A: See [Theme Configuration - VitePress Integration](/en/guide/theme/#vitepress-integration).
+A: See [Theme Configuration - VitePress Integration](/en/guide/theme#vitepress-integration).
 
 ### Q: Is XRequest still usable?
 

apps/docs/zh/guide/migration-v2.md

@@ -674,7 +674,7 @@ A: `XSender` 的 API 变化不大，主要是名称变更，同时新增了布
 
 ### Q: 如何在 VitePress 中接入暗色模式？
 
-A: 参见 [主题配置 - VitePress 接入](/zh/guide/theme/#vitepress-接入)。
+A: 参见 [主题配置 - VitePress 接入](/zh/guide/theme#vitepress-接入)。
 
 ### Q: XRequest 还能用吗？