feat: timeline 基础格式更新

backend/src/main/java/com/openisle/mapper/UserMapper.java

@@ -24,7 +24,7 @@ public class UserMapper {
   private final LevelService levelService;
   private final MedalService medalService;
 
-  @Value("${app.snippet-length:50}")
+  @Value("${app.snippet-length}")
   private int snippetLength;
 
   public AuthorDto toAuthorDto(User user) {

backend/src/main/java/com/openisle/service/SearchService.java

@@ -28,7 +28,7 @@ public class SearchService {
   private final CategoryRepository categoryRepository;
   private final TagRepository tagRepository;
 
-  @org.springframework.beans.factory.annotation.Value("${app.snippet-length:50}")
+  @org.springframework.beans.factory.annotation.Value("${app.snippet-length}")
   private int snippetLength;
 
   public List<User> searchUsers(String keyword) {

backend/src/main/resources/application.properties

@@ -43,7 +43,7 @@ app.avatar.base-url=${AVATAR_BASE_URL:https://api.dicebear.com/6.x}
 app.user.posts-limit=${USER_POSTS_LIMIT:10}
 app.user.replies-limit=${USER_REPLIES_LIMIT:50}
 # Length of extracted snippets for posts and search (-1 to disable truncation)
-app.snippet-length=${SNIPPET_LENGTH:50}
+app.snippet-length=${SNIPPET_LENGTH:200}
 
 # Captcha configuration
 app.captcha.enabled=${CAPTCHA_ENABLED:false}