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/public_payload_contract_test.go

@@ -0,0 +1,89 @@
+package services
+
+import (
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"io/fs"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+	"unicode"
+)
+
+// Public and persisted customer-service payload maps are part of the frontend
+// contract. Keep their literal keys in snake_case. Raw enterprise WeChat
+// inbound payloads retain the provider's original field names.
+func TestPublicPayloadMapKeysDoNotUseCamelCase(t *testing.T) {
+	dirs := []string{
+		".",
+		"../builders",
+		"../events",
+		"../handlers/api",
+		"../handlers/dashboard",
+		"../pkg/httpx",
+		"../pkg/utils",
+	}
+	for _, dir := range dirs {
+		fset := token.NewFileSet()
+		packages, err := parser.ParseDir(fset, dir, func(info fs.FileInfo) bool {
+			return !strings.HasSuffix(info.Name(), "_test.go")
+		}, 0)
+		if err != nil {
+			t.Fatalf("parse %s: %v", dir, err)
+		}
+		for _, pkg := range packages {
+			for filename, file := range pkg.Files {
+				if filepath.Base(filename) == "wxwork_kf_inbound_service.go" {
+					continue
+				}
+				ast.Inspect(file, func(node ast.Node) bool {
+					literal, ok := node.(*ast.CompositeLit)
+					if !ok || !isStringKeyedMap(literal.Type) {
+						return true
+					}
+					for _, element := range literal.Elts {
+						pair, ok := element.(*ast.KeyValueExpr)
+						if !ok {
+							continue
+						}
+						key, ok := pair.Key.(*ast.BasicLit)
+						if !ok || key.Kind != token.STRING {
+							continue
+						}
+						name, err := strconv.Unquote(key.Value)
+						if err != nil {
+							t.Errorf("%s: invalid map key %s: %v", filename, key.Value, err)
+							continue
+						}
+						// Dotted keys are internal i18n lookup identifiers, not JSON
+						// property names exposed to clients.
+						if !strings.Contains(name, ".") && containsUppercase(name) {
+							t.Errorf("%s: public payload map key %q must use snake_case", filename, name)
+						}
+					}
+					return true
+				})
+			}
+		}
+	}
+}
+
+func isStringKeyedMap(expression ast.Expr) bool {
+	mapType, ok := expression.(*ast.MapType)
+	if !ok {
+		return false
+	}
+	identifier, ok := mapType.Key.(*ast.Ident)
+	return ok && identifier.Name == "string"
+}
+
+func containsUppercase(value string) bool {
+	for _, r := range value {
+		if unicode.IsUpper(r) {
+			return true
+		}
+	}
+	return false
+}