feat(client): 更新 banner 去掉更新内容 + 安装程序中文化

- 顶部更新 banner 只显示「发现新版本 vX」，不再附带 release notes
- Inno Setup 安装向导改中文：随仓库带 ChineseSimplified.isl（加 UTF-8 BOM），
  .iss 用相对路径引用，compile-windows.sh 把它和 .iss 一起拷到构建目录，
  不依赖 runner 上 Inno Setup 是否自带简中
- （检查更新无更新时的提示已在上个提交加好）

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/ci/compile-windows.sh

@@ -58,6 +58,8 @@ fi
 # Run ISCC entirely under the clean build root: 32-bit ISCC would hit WOW64
 # redirection if it read the .iss / wrote output under the System32 workspace.
 cp deploy/windows/jiu-installer.iss "${BUILD_ROOT}/jiu-installer.iss"
+# 简体中文语言文件随 .iss 一起放到构建目录，供 [Languages] 按相对路径引用。
+cp deploy/windows/ChineseSimplified.isl "${BUILD_ROOT}/ChineseSimplified.isl"
 mkdir -p "${BUILD_ROOT}/dist"
 echo "==> building installer with Inno Setup (version ${VER})"
 # MSYS_NO_PATHCONV / MSYS2_ARG_CONV_EXCL disable Git Bash's automatic conversion