ci(backend): 调整 embed server

.gitignore

@@ -81,7 +81,12 @@ build/
 release/
 
 # 后端嵌入的前端构建产物
+# Keep a placeholder file so `//go:embed all:dist` always has a match in CI/lint,
+# while still ignoring generated frontend build outputs.
 backend/internal/web/dist/
+!backend/internal/web/dist/
+backend/internal/web/dist/*
+!backend/internal/web/dist/.keep
 
 # 后端运行时缓存数据
 backend/data/
@@ -92,4 +97,4 @@ backend/data/
 tests
 CLAUDE.md
 .claude
-scripts
+scripts