外观偏好异步补齐A：用户外观偏好服务端真源（user_appearance 实体+Appearance 三端点）

- 新实体 user_appearance（per-user 一行，theme_state/avatar_style 紧凑编码，NULL=跟随学校默认）
- 新增 GET appearance 聚合出参 + saveMyTheme/saveMyAvatarStyle 双写端点（登录态 /api/** 链路）
- 聚合读永不抛：个人段/学校段独立降级（identity 跨仓故障→学校段 null），脏值视同未配置
- Logo 择优复用 findLogoList 口径（本校 type=1 → 系统 type=0 → null），URL 拼法对齐 getLogoList
- ThemeCodec 编解码下沉 + resolveThemeSchId/resolveSchId 下沉 SchSettingsService（行为等价重构，供共享）
- 单测：ThemeCodecTest 5 例 + AppearanceServiceTest 9 例（聚合降级/upsert 置 NULL/择优/校验从严）

src/main/java/com/yunhai/userhome/service/impl/SchSettingsServiceImpl.java

@@ -1,8 +1,11 @@
 package com.yunhai.userhome.service.impl;
 
+import com.yunhai.platform.utils.model.BoaUser;
 import com.yunhai.userhome.entity.SchSettings;
+import com.yunhai.userhome.entity.UserCurrentRole;
 import com.yunhai.userhome.repository.SchSettingsRepository;
 import com.yunhai.userhome.service.ISchSettingsService;
+import com.yunhai.userhome.service.IUserCurrentRoleService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
@@ -18,6 +21,9 @@ public class SchSettingsServiceImpl implements ISchSettingsService {
     @Autowired
     private SchSettingsRepository schSettingsRepository;
 
+    @Autowired
+    private IUserCurrentRoleService userCurrentRoleService;
+
     @Override
     public void save(SchSettings schSettings) {
         schSettingsRepository.save(schSettings);
@@ -46,4 +52,26 @@ public class SchSettingsServiceImpl implements ISchSettingsService {
     public java.util.List<SchSettings> findBySchIds(java.util.List<Integer> schId) {
         return schSettingsRepository.getSchSettingList(schId);
     }
+
+    @Override
+    public Integer resolveSchId(BoaUser user) {
+        if (user.getSchool() != null) {
+            return user.getSchool().getId();
+        }
+        if (user.getBureau() != null) {
+            return user.getBureau().getId();
+        }
+        return 0;
+    }
+
+    @Override
+    public Integer resolveThemeSchId(BoaUser user, Integer explicitSchId) {
+        if (user.getType() != null && user.getType() == 1) {
+            return explicitSchId == null ? 0 : explicitSchId;
+        }
+        return userCurrentRoleService.findById(user.getId())
+                .map(UserCurrentRole::getSchId)
+                .filter(schId -> schId != null && schId > 0)
+                .orElseGet(() -> resolveSchId(user));
+    }
 }