前端风格更改

.trellis/spec/frontend/component-guidelines.md

@@ -16,8 +16,14 @@ the reusable UI units.
 
 - Use shared fragments for repeated layout pieces such as header, navigation,
   sidebar, footer, pagination, and message banners.
-- Prefer `.jspf` includes or JSP tag files once the project chooses one
-  pattern; document the actual paths after implementation.
+- Use `.jspf` includes for the current JSP presentation layer. The authenticated
+  application frame lives in `src/main/webapp/WEB-INF/jsp/common/header.jspf`
+  and owns the dark sidebar, top utility bar, role workbench links, module
+  navigation, global search, user display, and logout link.
+- Preserve role-conditioned navigation in that shared frame: administrator-only
+  links stay inside `sessionScope.userRole == 'administrator'`; staff links stay
+  inside `administrator or librarian`; reader-only links stay inside
+  `sessionScope.userRole == 'reader'`.
 - Keep fragments presentation-focused. They should not open database
   connections or call DAOs.