Add floating translate panel and harden production frontend updates

Move translation to a left-side FAB with compact inline input, remove redundant nav and dashboard entry points, and improve deploy cache headers plus stale chunk recovery on login flows.

Co-authored-by: Cursor <cursoragent@cursor.com>

deploy/wordloop-locations.inc

@@ -23,15 +23,26 @@ location /openapi.json {
     proxy_set_header Host $host;
 }
 
+# 入口 HTML 禁止缓存（避免部署后仍引用已删除的旧 chunk）
+location = /index.html {
+    add_header Cache-Control "no-store, no-cache, must-revalidate, max-age=0" always;
+    add_header CDN-Cache-Control "no-store" always;
+    add_header Pragma "no-cache" always;
+    add_header Expires "0" always;
+}
+
 # 静态资源不存在时必须 404，不能回退 index.html（否则 JS 加载失败页面空白）
 location ^~ /assets/ {
     try_files $uri =404;
     expires 7d;
-    add_header Cache-Control "public, immutable";
+    add_header Cache-Control "public, max-age=604800, immutable" always;
 }
 
 # Vue Router history：/login 等路径回退 index.html
 location / {
     try_files $uri $uri/ /index.html;
-    add_header Cache-Control "no-store, no-cache, must-revalidate";
+    add_header Cache-Control "no-store, no-cache, must-revalidate, max-age=0" always;
+    add_header CDN-Cache-Control "no-store" always;
+    add_header Pragma "no-cache" always;
+    add_header Expires "0" always;
 }