refactor: 移除业务ID字段并优化DAO层实现

model/entity/file.go

@@ -8,7 +8,6 @@ import (
 type File struct {
 	beans.SQLBaseDO `orm:",inherit"` // 嵌入基础字段：Id, Bid, Creator, CreatedAt, Updater, UpdatedAt, Deleter, DeletedAt, IsDeleted
 	// 业务字段
-	Bid      string `orm:"bid" json:"bid"`
 	TenantId uint64 `orm:"tenant_id" json:"tenantId"` // 租户ID
 	FileURL  string `orm:"file_url"  json:"fileURL"`  // 文件URL
 	FileSize int    `orm:"file_size" json:"fileSize"`
@@ -16,7 +15,6 @@ type File struct {
 
 type fileCol struct {
 	beans.SQLBaseCol
-	Bid      string
 	TenantId string
 	FileURL  string
 	FileSize string
@@ -24,7 +22,6 @@ type fileCol struct {
 
 var FileCol = fileCol{
 	SQLBaseCol: beans.DefSQLBaseCol,
-	Bid:        "bid",
 	TenantId:   "tenant_id",
 	FileURL:    "file_url",
 	FileSize:   "file_size",