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/wxwork/wxwork.go

@@ -1,31 +1,72 @@
 package wxwork
 
 import (
-	"code.tczkiot.com/wlw/ai-agent/internal/pkg/config"
+	"context"
+	"log/slog"
+	"reflect"
 	"strings"
+	"sync"
+
+	"code.tczkiot.com/wlw/ai-agent/internal/pkg/config"
 
 	"github.com/silenceper/wechat/v2/cache"
 	"github.com/silenceper/wechat/v2/work"
 	wxconfig "github.com/silenceper/wechat/v2/work/config"
 )
 
-var (
-	w     *work.Work
-	wxCfg config.WxWorkConfig
-)
+type SettingsLoader func(ctx context.Context, prefix string) (map[string]string, error)
+
+var runtime = struct {
+	sync.RWMutex
+	loader SettingsLoader
+	client *work.Work
+	config config.WxWorkConfig
+}{}
+
+// SetSettingsLoader enables demand-driven settings reads for embedded mode.
+// No save hook or hot-reload process is required: each enterprise WeChat
+// business call observes the latest values in the host settings table.
+func SetSettingsLoader(loader SettingsLoader) {
+	runtime.Lock()
+	runtime.loader = loader
+	runtime.Unlock()
+}
 
 func Init() {
-	w = nil
-	wxCfg = config.WxWorkConfig{}
-	cfg := config.Current()
-	if !cfg.WxWork.Enabled {
-		return
+	if err := refresh(); err != nil {
+		slog.Error("init enterprise WeChat settings failed", "error", err)
 	}
-	wxCfg = cfg.WxWork
-	if strings.TrimSpace(wxCfg.CorpID) == "" || strings.TrimSpace(wxCfg.CorpSecret) == "" {
-		return
+}
+
+func refresh() error {
+	runtime.RLock()
+	loader := runtime.loader
+	runtime.RUnlock()
+
+	wxCfg := config.Current().WxWork
+	if loader != nil {
+		settings, err := loader(context.Background(), config.SettingsPrefix)
+		if err != nil {
+			return err
+		}
+		cfg, err := config.FromSettings(settings)
+		if err != nil {
+			return err
+		}
+		wxCfg = cfg.WxWork
 	}
-	w = work.NewWork(&wxconfig.Config{
+
+	runtime.Lock()
+	defer runtime.Unlock()
+	if reflect.DeepEqual(runtime.config, wxCfg) {
+		return nil
+	}
+	runtime.config = wxCfg
+	runtime.client = nil
+	if !wxCfg.Enabled || strings.TrimSpace(wxCfg.CorpID) == "" || strings.TrimSpace(wxCfg.CorpSecret) == "" {
+		return nil
+	}
+	runtime.client = work.NewWork(&wxconfig.Config{
 		CorpID:         wxCfg.CorpID,
 		CorpSecret:     wxCfg.CorpSecret,
 		AgentID:        wxCfg.AgentID,
@@ -34,12 +75,35 @@ func Init() {
 		EncodingAESKey: wxCfg.EncodingAESKey,
 		Cache:          cache.NewMemory(),
 	})
+	return nil
 }
 
 func Enabled() bool {
-	return w != nil && wxCfg.Enabled
+	if err := refresh(); err != nil {
+		slog.Error("read enterprise WeChat settings failed", "error", err)
+		return false
+	}
+	runtime.RLock()
+	defer runtime.RUnlock()
+	return runtime.client != nil && runtime.config.Enabled
 }
 
 func GetWorkCli() *work.Work {
-	return w
+	if err := refresh(); err != nil {
+		slog.Error("read enterprise WeChat settings failed", "error", err)
+		return nil
+	}
+	runtime.RLock()
+	defer runtime.RUnlock()
+	return runtime.client
+}
+
+// CurrentConfig returns the latest enterprise WeChat settings from the host.
+func CurrentConfig() (config.WxWorkConfig, error) {
+	if err := refresh(); err != nil {
+		return config.WxWorkConfig{}, err
+	}
+	runtime.RLock()
+	defer runtime.RUnlock()
+	return runtime.config, nil
 }