feat(ui): ReplyPier 品牌、中文界面与前端构建产物

替换品牌文案与图标，补齐窄屏布局和加载失败提示，确认主要旅程可操作。

frontend/src/assets/view.svg

@@ -0,0 +1,3 @@
+<?xml version="1.0"?><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30px" height="30px">
+    <path d="M 15 5 C 6.081703 5 0.32098813 14.21118 0.21679688 14.378906 A 1 1 0 0 0 0.21679688 15.621094 C 0.32098813 15.78882 6.081703 25 15 25 C 23.918297 25 29.679012 15.78882 29.783203 15.621094 A 1 1 0 0 0 29.783203 14.378906 C 29.679012 14.21118 23.918297 5 15 5 z M 15 8 C 18.866 8 22 11.134 22 15 C 22 18.866 18.866 22 15 22 C 11.134 22 8 18.866 8 15 C 8 11.134 11.134 8 15 8 z M 15 12 A 3 3 0 0 0 12 15 A 3 3 0 0 0 15 18 A 3 3 0 0 0 18 15 A 3 3 0 0 0 15 12 z"/>
+</svg>