feat(skeleton): Astro 7.3.8 项目初始化（pnpm+TS strict）

- astro 锁 7.3.8：7.4 起 engines 要求 node>=22.23.4，宿主 22.22.3 差一档
- minimal 骨架：单页占位 + site=https://wait4x.online，集成留 T8 按任务接入

验证: pnpm astro build exit 0（1 page built）

Spec: 2026-10-24_add-blog-skeleton
Co-authored-by: GLM-5.3

package.json

@@ -0,0 +1,15 @@
+{
+  "name": "wait4x-blog",
+  "type": "module",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "astro dev",
+    "build": "astro build",
+    "preview": "astro preview",
+    "astro": "astro"
+  },
+  "dependencies": {
+    "astro": "^7.3.8"
+  }
+}