refactor: 将客服后端重构为宿主可嵌入模块

- 注入数据库、运行时配置、统一响应、文件存储和平台 AI 能力，补充业务读写工具与客户快捷操作契约。

- 移除模块内重复的组织、客户、工单、标签、技能、旧工作流、MCP 和迁移实现，将身份权限与业务主体交由宿主管理。

- 使用 libSQL 重构向量存储，并完善图片消息、访客身份、排队调度、企业微信和支持聊天页面。

- 统一 HTTP、DTO 与 WebSocket 的 snake_case 协议，补齐模块初始化、业务动作和公共载荷等回归测试。

internal/services/asset_service.go

@@ -1,6 +1,14 @@
 package services
 
 import (
+	"bufio"
+	"bytes"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"strings"
+	"time"
+
 	"code.tczkiot.com/wlw/ai-agent/internal/models"
 	"code.tczkiot.com/wlw/ai-agent/internal/pkg/config"
 	"code.tczkiot.com/wlw/ai-agent/internal/pkg/dto"
@@ -9,13 +17,6 @@ import (
 	"code.tczkiot.com/wlw/ai-agent/internal/pkg/utils"
 	"code.tczkiot.com/wlw/ai-agent/internal/repositories"
 	"code.tczkiot.com/wlw/ai-agent/internal/services/storage"
-	"bytes"
-	"io"
-	"mime/multipart"
-	"net/http"
-	"strings"
-	"time"
-
 	"github.com/google/uuid"
 	"github.com/mlogclub/simple/sqls"
 )
@@ -46,32 +47,58 @@ func (s *assetService) FindPageByCnd(cnd *sqls.Cnd) (list []models.Asset, paging
 }
 
 func (s *assetService) OpenReader(asset *models.Asset) (io.ReadCloser, error) {
-	cfg := config.Current()
 	if asset == nil {
 		return nil, errorsx.InvalidParamI18n("error.e0146")
 	}
-	switch asset.Provider {
-	case "", enums.AssetProviderLocal:
-		return storage.NewLocalStorage(cfg.Storage.Local).Read(asset.StorageKey)
-	case enums.AssetProviderOSS:
-		return storage.NewOSSStorage(cfg.Storage.OSS).Read(asset.StorageKey)
-	default:
-		return nil, errorsx.InvalidParamI18n("error.e0195")
+	provider, err := storage.NewProvider(asset.Provider)
+	if err != nil {
+		return nil, err
 	}
+	return provider.Read(asset.StorageKey)
 }
 
 func (s *assetService) UploadBytes(data []byte, prefix, filename string, principal *dto.AuthPrincipal) (*models.Asset, error) {
+	return s.uploadBytes(data, prefix, filename, 0, principal)
+}
+
+func (s *assetService) UploadConversationBytes(data []byte, prefix, filename string, conversationID int64, principal *dto.AuthPrincipal) (*models.Asset, error) {
+	if conversationID <= 0 {
+		return nil, errorsx.InvalidParamI18n("error.e0064")
+	}
+	return s.uploadBytes(data, prefix, filename, conversationID, principal)
+}
+
+func (s *assetService) uploadBytes(data []byte, prefix, filename string, conversationID int64, principal *dto.AuthPrincipal) (*models.Asset, error) {
 	src := bytes.NewReader(data)
 	return s.Upload(src, storage.UploadInfo{
-		Prefix:    prefix,
-		Filename:  filename,
-		FileSize:  int64(len(data)),
-		MimeType:  http.DetectContentType(data),
-		Principal: principal,
+		Prefix:         prefix,
+		ConversationID: conversationID,
+		Filename:       filename,
+		FileSize:       int64(len(data)),
+		MimeType:       http.DetectContentType(data),
+		Principal:      principal,
 	})
 }
 
 func (s *assetService) UploadFile(file *multipart.FileHeader, prefix string, principal *dto.AuthPrincipal) (*models.Asset, error) {
+	return s.uploadFile(file, prefix, 0, false, principal)
+}
+
+func (s *assetService) UploadConversationFile(file *multipart.FileHeader, prefix string, conversationID int64, principal *dto.AuthPrincipal) (*models.Asset, error) {
+	if conversationID <= 0 {
+		return nil, errorsx.InvalidParamI18n("error.e0064")
+	}
+	return s.uploadFile(file, prefix, conversationID, false, principal)
+}
+
+func (s *assetService) UploadConversationImageFile(file *multipart.FileHeader, prefix string, conversationID int64, principal *dto.AuthPrincipal) (*models.Asset, error) {
+	if conversationID <= 0 {
+		return nil, errorsx.InvalidParamI18n("error.e0064")
+	}
+	return s.uploadFile(file, prefix, conversationID, true, principal)
+}
+
+func (s *assetService) uploadFile(file *multipart.FileHeader, prefix string, conversationID int64, imageOnly bool, principal *dto.AuthPrincipal) (*models.Asset, error) {
 	if file == nil {
 		return nil, errorsx.InvalidParamI18n("error.e0323")
 	}
@@ -87,12 +114,20 @@ func (s *assetService) UploadFile(file *multipart.FileHeader, prefix string, pri
 	}
 	defer func() { _ = src.Close() }()
 
-	return s.Upload(src, storage.UploadInfo{
-		Prefix:    prefix,
-		Filename:  file.Filename,
-		FileSize:  file.Size,
-		MimeType:  file.Header.Get("Content-Type"),
-		Principal: principal,
+	reader := bufio.NewReader(src)
+	header, _ := reader.Peek(512)
+	mimeType := strings.TrimSpace(strings.Split(http.DetectContentType(header), ";")[0])
+	if imageOnly && !isSupportedVisionImageMIME(mimeType) {
+		return nil, errorsx.InvalidParamI18n("error.e0090")
+	}
+
+	return s.Upload(reader, storage.UploadInfo{
+		Prefix:         prefix,
+		ConversationID: conversationID,
+		Filename:       file.Filename,
+		FileSize:       file.Size,
+		MimeType:       mimeType,
+		Principal:      principal,
 	})
 }
 
@@ -104,25 +139,27 @@ func (s *assetService) Upload(reader io.Reader, info storage.UploadInfo) (*model
 
 	assetID, key := storage.GenerateStorageKey(info)
 	item := &models.Asset{
-		AssetID:     assetID,
-		Provider:    provider.ProviderType(),
-		StorageKey:  key,
-		Filename:    info.Filename,
-		FileSize:    info.FileSize,
-		MimeType:    info.MimeType,
-		Status:      enums.AssetStatusPending,
-		AuditFields: utils.BuildAuditFields(info.Principal),
+		ConversationID: info.ConversationID,
+		AssetID:        assetID,
+		Provider:       provider.ProviderType(),
+		StorageKey:     key,
+		Filename:       info.Filename,
+		FileSize:       info.FileSize,
+		MimeType:       info.MimeType,
+		Status:         enums.AssetStatusPending,
+		AuditFields:    utils.BuildAuditFields(info.Principal),
 	}
 	if err := repositories.AssetRepository.Create(sqls.DB(), item); err != nil {
 		return nil, err
 	}
 
 	if _, err := provider.Upload(reader, key, storage.UploadInfo{
-		Prefix:    info.Prefix,
-		Filename:  info.Filename,
-		FileSize:  info.FileSize,
-		MimeType:  info.MimeType,
-		Principal: info.Principal,
+		Prefix:         info.Prefix,
+		ConversationID: info.ConversationID,
+		Filename:       info.Filename,
+		FileSize:       info.FileSize,
+		MimeType:       info.MimeType,
+		Principal:      info.Principal,
 	}); err != nil {
 		_ = s.markAssetStatus(item.ID, enums.AssetStatusFailed, info.Principal)
 		return nil, err
@@ -134,6 +171,15 @@ func (s *assetService) Upload(reader io.Reader, info storage.UploadInfo) (*model
 	return item, nil
 }
 
+func isSupportedVisionImageMIME(mimeType string) bool {
+	switch strings.ToLower(strings.TrimSpace(strings.Split(mimeType, ";")[0])) {
+	case "image/jpeg", "image/png", "image/gif", "image/webp":
+		return true
+	default:
+		return false
+	}
+}
+
 func (s *assetService) GetSignedURL(id int64) (string, error) {
 	item := s.Get(id)
 	if item == nil {