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/storage/provider.go

@@ -1,13 +1,18 @@
 package storage
 
 import (
+	"context"
+	"fmt"
+	"io"
+
+	"code.tczkiot.com/wlw/ai-agent/contract"
 	"code.tczkiot.com/wlw/ai-agent/internal/pkg/config"
 	"code.tczkiot.com/wlw/ai-agent/internal/pkg/enums"
 	"code.tczkiot.com/wlw/ai-agent/internal/pkg/errorsx"
-	"io"
 )
 
 var providers = make(map[enums.AssetProvider]FileStorageProvider)
+var hostStorage contract.FileStorage
 
 type FileStorageProvider interface {
 	ProviderType() enums.AssetProvider
@@ -18,7 +23,24 @@ type FileStorageProvider interface {
 	Read(key string) (io.ReadCloser, error)
 }
 
+// SetHostStorage lets the embedding system own file persistence. Passing nil
+// preserves the standalone module's built-in local/OSS providers.
+func SetHostStorage(value contract.FileStorage) {
+	hostStorage = value
+	providers = make(map[enums.AssetProvider]FileStorageProvider)
+}
+
 func GetDefault() (FileStorageProvider, error) {
+	if hostStorage != nil {
+		provider, err := hostStorage.DefaultProvider(context.Background())
+		if err != nil {
+			return nil, err
+		}
+		if provider == "" {
+			return nil, fmt.Errorf("host file storage returned an empty default provider")
+		}
+		return GetProvider(enums.AssetProvider(provider))
+	}
 	return NewProvider(config.Current().Storage.Default)
 }
 
@@ -37,6 +59,12 @@ func GetProvider(providerType enums.AssetProvider) (FileStorageProvider, error)
 }
 
 func NewProvider(provider enums.AssetProvider) (FileStorageProvider, error) {
+	if hostStorage != nil {
+		if provider == "" {
+			return GetDefault()
+		}
+		return &hostFileStorageProvider{provider: provider}, nil
+	}
 	cfg := config.Current().Storage
 
 	switch provider {
@@ -48,3 +76,45 @@ func NewProvider(provider enums.AssetProvider) (FileStorageProvider, error) {
 		return nil, errorsx.InvalidParamI18n("error.e0082")
 	}
 }
+
+type hostFileStorageProvider struct {
+	provider enums.AssetProvider
+}
+
+func (p *hostFileStorageProvider) ProviderType() enums.AssetProvider {
+	return p.provider
+}
+
+func (p *hostFileStorageProvider) Upload(reader io.Reader, key string, info UploadInfo) (*StoredFile, error) {
+	accessURL, err := hostStorage.Upload(
+		context.Background(), string(p.provider), key, info.Filename, info.MimeType, info.FileSize, reader,
+	)
+	if err != nil {
+		return nil, err
+	}
+	return &StoredFile{
+		Provider:   p.provider,
+		StorageKey: key,
+		URL:        accessURL,
+		Filename:   info.Filename,
+		FileSize:   info.FileSize,
+		MimeType:   info.MimeType,
+	}, nil
+}
+
+func (p *hostFileStorageProvider) GetURL(key string) string {
+	value, _ := hostStorage.URL(context.Background(), string(p.provider), key)
+	return value
+}
+
+func (p *hostFileStorageProvider) GetSignedURL(key string) string {
+	return p.GetURL(key)
+}
+
+func (p *hostFileStorageProvider) Delete(key string) error {
+	return hostStorage.Delete(context.Background(), string(p.provider), key)
+}
+
+func (p *hostFileStorageProvider) Read(key string) (io.ReadCloser, error) {
+	return hostStorage.Open(context.Background(), string(p.provider), key)
+}