feat(Materials): add new materials navigation and href functions

- Introduced href functions for accessing materials, including hrefMaterials, hrefMaterialSubject, and hrefMaterialDetail.
- Updated AppsScreen to include a new entry for materials, enhancing the app's educational resources section.
- Exported material types in index.ts to support the new materials functionality.

src/navigation/hrefs.ts

@@ -155,3 +155,17 @@ export function hrefAuthRegister(): string {
 export function hrefAuthForgot(): string {
   return '/forgot-password';
 }
+
+// ==================== Materials (学习资料) ====================
+
+export function hrefMaterials(): string {
+  return '/apps/materials';
+}
+
+export function hrefMaterialSubject(subjectId: string): string {
+  return `/apps/materials/subject?subjectId=${encodeURIComponent(subjectId)}`;
+}
+
+export function hrefMaterialDetail(materialId: string): string {
+  return `/apps/materials/detail?materialId=${encodeURIComponent(materialId)}`;
+}