fix: 修复登录500错误和移除明文密码提示

- 修复 deps.py 中 get_vn_service 的引用错误 (vn_service.vn_service -> vn_service)
- 移除登录页面上的明文密码提示
- 改进前端错误处理，避免数据加载失败导致登录显示错误

.gitignore

@@ -76,8 +76,9 @@ logs/
 temp/
 tmp/
 
-# VeighNa upstream (don't modify directly)
-vnpy_v4.4.0/
+# VeighNa upstream (included for version reference)
+# Managed as version-controlled reference
+# vnpy_v4.4.0/.git is excluded to avoid nested repo
 
 # Knowledge base repositories
 knowledge_base/
@@ -94,3 +95,7 @@ setting/
 *.json
 !pyproject.toml
 !package.json
+
+# Docker deployment files (may contain sensitive paths)
+docker/.env
+!docker/.env.example