refactor: SubmitResult sealed接口强类型替代ApiResponse<Object>

par-core/src/main/java/com/par/core/dto/SubmitResult.java

@@ -0,0 +1,13 @@
+package com.par.core.dto;
+
+/**
+ * 访问结果提交返回类型，统一处理"正常存储"和"去重跳过"两种场景
+ */
+public sealed interface SubmitResult permits SubmitResult.Success, SubmitResult.Skipped {
+
+    /** 正常存储，返回 DTO */
+    record Success(AccessResultDTO dto) implements SubmitResult {}
+
+    /** 内容重复，跳过存储 */
+    record Skipped(String reason) implements SubmitResult {}
+}