feat: 合同变更记录对齐项目变更，自动生成变更内容并记录变更字段

blade-service/blade-transport/src/main/java/org/springblade/transport/service/impl/ContractManageServiceImpl.java

@@ -67,6 +67,7 @@ import java.util.Objects;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 /**
  * 合同管理 服务实现类
@@ -1279,11 +1280,12 @@ public class ContractManageServiceImpl extends BaseServiceImpl<ContractManageMap
 		record.put("handlerUserId", AuthUtil.getUserId());
 		record.put("handlerUserName", AuthUtil.getUserName());
 		record.put("changeType", changeType);
-		record.put("changeContent", TransportBusinessSupport.trimToNull(contractManage.getChangeContent()));
+		record.put("changeContent", resolveChangeRecordContent(contractManage, beforeData, afterData));
 		record.put("changeReason", TransportBusinessSupport.trimToNull(changeReason));
 		record.put("status", status);
 		record.put("statusName", statusName);
 		if (beforeData != null && afterData != null) {
+			record.put("changedFields", new ArrayList<>(beforeData.keySet()));
 			record.put("beforeData", beforeData);
 			record.put("afterData", afterData);
 		}
@@ -1291,6 +1293,54 @@ public class ContractManageServiceImpl extends BaseServiceImpl<ContractManageMap
 		contractManage.setChangeRecordJson(JsonUtil.toJson(records));
 	}
 
+	/**
+	 * 变更记录内容：有前后快照时生成「将【字段】由【旧值】变更为【新值】」对比文本（与项目变更记录一致），
+	 * 无快照（创建/回调等）时沿用填写的变更内容
+	 */
+	private String resolveChangeRecordContent(ContractManage contractManage, Map<String, Object> beforeData,
+											  Map<String, Object> afterData) {
+		if (beforeData == null || afterData == null || beforeData.isEmpty()) {
+			return TransportBusinessSupport.trimToNull(contractManage.getChangeContent());
+		}
+		return beforeData.entrySet().stream()
+			.map(entry -> "将【" + contractChangeFieldLabel(entry.getKey()) + "】由【" + formatChangeRecordValue(entry.getValue())
+				+ "】变更为【" + formatChangeRecordValue(afterData.get(entry.getKey())) + "】")
+			.collect(Collectors.joining("、"));
+	}
+
+	/**
+	 * 合同变更快照字段中文名（change_record_json 展示用，与前端变更字段标签一致）
+	 */
+	private static final Map<String, String> CONTRACT_CHANGE_FIELD_LABELS = Map.ofEntries(
+		Map.entry("contractNo", "合同编号"), Map.entry("contractName", "合同名称"),
+		Map.entry("partyB", "乙方"), Map.entry("startDate", "开始日期"),
+		Map.entry("endDate", "结束日期"), Map.entry("contractFormat", "合同格式"),
+		Map.entry("settlementMode", "结算方式"), Map.entry("legalSealFlag", "是否需要加盖法人章"),
+		Map.entry("copyCount", "一式份数"), Map.entry("settlementCurrency", "结算币种"),
+		Map.entry("invoiceCycle", "开票周期(天)"), Map.entry("paymentDays", "回款账期(天)"),
+		Map.entry("contractAmount", "合同金额"), Map.entry("templateFlag", "是否范本"),
+		Map.entry("originalContractNo", "原件合同编号"), Map.entry("electronicSealFlag", "是否电子章"),
+		Map.entry("mainContent", "合同主要内容"), Map.entry("remark", "其他事项说明"),
+		Map.entry("feeGenerationMode", "费用生成模式"), Map.entry("billingPlanJson", "计费方案"),
+		Map.entry("settlementRuleJson", "结算生成规则"), Map.entry("preSettlementConfigJson", "预结算配置"),
+		Map.entry("formalSettlementConfigJson", "正式结算配置"), Map.entry("paymentRatioJson", "付款比例设置"),
+		Map.entry("contractFileJson", "合同主文件"), Map.entry("attachmentsJson", "其它附件"),
+		Map.entry("changeAttachmentsJson", "变更附件")
+	);
+
+	private String contractChangeFieldLabel(String field) {
+		return CONTRACT_CHANGE_FIELD_LABELS.getOrDefault(field, field);
+	}
+
+	private String formatChangeRecordValue(Object value) {
+		if (value == null || (value instanceof String text && text.isBlank())) {
+			return "空";
+		}
+		String text = String.valueOf(value);
+		// 计费方案/附件等长 JSON 文本截断，保证变更内容可读
+		return text.length() > 100 ? text.substring(0, 100) + "…" : text;
+	}
+
 	private Map<String, Object> buildContractChangeSnapshot(ContractManage contractManage) {
 		Map<String, Object> data = new LinkedHashMap<>();
 		data.put("contractNo", contractManage.getContractNo());