feat: H5热更新 v7→v8 — 版本号推进

- ota/version.txt → 0.1.0-dav-android-8
- ota/h5/index-v8.html → 紫色标题+v8徽章，含自更新按钮
- embedded index.html → 下载目标改为 v8

packages/client-android/android/app/src/main/assets/index.html

@@ -27,7 +27,7 @@ function checkUpdate(){
  .then(r=>{if(!r.ok)throw Error('HTTP '+r.status);return r.text()})
  .then(t=>{t=t.trim();log('remote: '+t);
   var local=document.getElementById('ver').innerText;
-  if(t!==local&&t!=='v'+local&&'v'+t!==local){dlVer=t;dlUrl=BASE+'/h5/index-v7.html';
+  if(t!==local&&t!=='v'+local&&'v'+t!==local){dlVer=t;dlUrl=BASE+'/h5/index-v8.html';
    log('*** NEW VERSION: '+dlVer+' ***');document.getElementById('btnApply').disabled=false}
   else log('up to date')})
  .catch(e=>log('ERR: '+e.message))