feat: 添加合约文件类型服务及错误处理改进

refactor: 重构合约文件类型相关代码，优化错误处理逻辑

fix: 修复WebSocket会话未绑定用户时的错误处理

style: 调整代码格式，提高可读性

docs: 更新部分代码注释

test: 添加合约文件类型服务的测试用例

chore: 移除无用代码，清理项目结构

client/src/main/java/com/ecep/contract/service/ContractFileService.java

@@ -1,32 +1,30 @@
 package com.ecep.contract.service;
 
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
 
 import com.ecep.contract.ContractFileType;
 import com.ecep.contract.model.Contract;
 import com.ecep.contract.model.ContractFile;
-import com.ecep.contract.model.ContractFileTypeLocal;
 import com.ecep.contract.vm.ContractFileViewModel;
 
 @Service
 public class ContractFileService extends QueryService<ContractFile, ContractFileViewModel> {
-
     public List<ContractFile> findAllByContract(Contract contract) {
-        // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'findAllByContract'");
-    }
-
-    public Map<ContractFileType, ContractFileTypeLocal> findAllFileTypes(String languageTag) {
-        // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'findAllFileTypes'");
+        Map<String, Object> params = new HashMap<>();
+        params.put("contract", contract.getId());
+        return findAll(params, Pageable.unpaged()).getContent();
     }
 
     public List<ContractFile> findAllByContractAndFileType(Contract contract, ContractFileType type) {
-        // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'findAllByContractAndFileType'");
+        Map<String, Object> params = new HashMap<>();
+        params.put("contract", contract.getId());
+        params.put("type", type.name());
+        return findAll(params, Pageable.unpaged()).getContent();
     }
 
 }