fix(dashboard): 统计应用数量时排除系统应用(is_default=1)

DashboardService.stats() 中过滤 isDefault=true 的系统应用，
与 AppService.listByTenant() 保持一致，避免控制台 dashboard
与应用列表页显示数量不符。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tenant-service/src/main/java/com/xuqm/tenant/service/DashboardService.java

@@ -30,7 +30,9 @@ public class DashboardService {
     }
 
     public Map<String, Object> stats(String tenantId) {
-        List<AppEntity> apps = appRepository.findByTenantId(tenantId);
+        List<AppEntity> apps = appRepository.findByTenantId(tenantId).stream()
+                .filter(app -> !app.isDefault())
+                .toList();
         long serviceCount = 0;
         for (AppEntity app : apps) {
             serviceCount += featureServiceRepository.findByAppKey(app.getId()).stream()