修复 H5 嵌入小程序导航栏冲突

- 识别微信小程序 web-view 宿主环境
- 宿主导航存在时隐藏 H5 自绘返回与页面标题
- 收回详情、搜索、讲解列表页面顶部预留空间

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

src/utils/hostEnvironment.ts

@@ -0,0 +1,34 @@
+const getCurrentUrlSearchParams = () => {
+  if (typeof window === 'undefined') return new URLSearchParams()
+
+  const params = new URLSearchParams(window.location.search)
+  const hash = window.location.hash || ''
+  const hashQueryStart = hash.indexOf('?')
+
+  if (hashQueryStart >= 0) {
+    const hashParams = new URLSearchParams(hash.slice(hashQueryStart + 1))
+    hashParams.forEach((value, key) => {
+      if (!params.has(key)) params.set(key, value)
+    })
+  }
+
+  return params
+}
+
+export const isEmbeddedInWechatMiniProgram = () => {
+  if (typeof window === 'undefined') return false
+
+  const params = getCurrentUrlSearchParams()
+  const embedded = params.get('embedded') || params.get('embed') || params.get('host')
+  if (embedded === 'wechat-mini-program' || embedded === 'weapp' || embedded === 'mini-program') {
+    return true
+  }
+
+  const wxEnvironment = (window as Window & {
+    __wxjs_environment?: string
+  }).__wxjs_environment
+
+  if (wxEnvironment === 'miniprogram') return true
+
+  return /miniProgram/i.test(window.navigator?.userAgent || '')
+}