fun: HTTP RPC framework with DI, guards, streams and codegen

- Service binding via reflection with 4 method signatures
- Dependency injection (Wired/auto tags) and guards
- Streamable HTTP (NDJSON) streaming responses
- Go/TypeScript client code generation (self-contained, with interceptors)
- Enum support, structured Result, logging
- 16 regression tests covering all fixed bugs

result.go

@@ -0,0 +1,60 @@
+package fun
+
+import (
+	"fmt"
+	"reflect"
+)
+
+const (
+	successCode uint8 = iota
+	cellErrorCode
+	errorCode
+)
+
+type Result[T any] struct {
+	Id     string  `json:"id,omitempty"`
+	Code   *uint16 `json:"code,omitempty"`
+	Data   *T      `json:"data,omitempty"`
+	Msg    *string `json:"msg,omitempty"`
+	Status uint8   `json:"status"`
+}
+
+// Error 让 Result 实现 error 接口，业务方法可直接返回，Code/Msg/Status 随结果透传
+func (r Result[T]) Error() string {
+	if r.Msg != nil {
+		return *r.Msg
+	}
+	if r.Code != nil {
+		return fmt.Sprintf("code=%d", *r.Code)
+	}
+	return "fun: unknown error"
+}
+
+// Error 构造带错误码的错误响应，作为 error 返回
+// 用法：return "", fun.Error(4001, "登录失败")
+func Error(code uint16, msg string) error {
+	return Result[any]{Code: &code, Msg: &msg, Status: errorCode}
+}
+
+func callError(err error) Result[any] {
+	return Result[any]{Msg: new(err.Error()), Status: cellErrorCode}
+}
+
+// success 构造成功响应,空切片规范化为 [] 而不是 null
+func success(data any) Result[any] {
+	return Result[any]{Data: nonNil(data), Status: successCode}
+}
+
+// nonNil 返回 data 的指针;空切片会重建为同类型的非 nil 空切片,
+// 保证 JSON 序列化输出 [] 而不是 null
+func nonNil(data any) *any {
+	if data == nil {
+		return nil
+	}
+
+	v := reflect.ValueOf(data)
+	if v.Kind() == reflect.Slice && v.Len() == 0 {
+		return new(reflect.MakeSlice(v.Type(), 0, 0).Interface())
+	}
+	return &data
+}