Version: 0.9.66.dev.260504

后端：
1. 阶段 2 user/auth 服务边界落地，新增 `cmd/userauth` go-zero zrpc 服务、`services/userauth` 核心实现、gateway user API/zrpc client 与 shared contracts/ports，迁移注册、登录、刷新 token、登出、JWT、黑名单和 token 额度治理
2. gateway 与启动装配切流，`cmd/all` 只保留边缘路由、鉴权和轻量组合，通过 userauth zrpc 访问核心用户能力；拆分 MySQL/Redis 初始化与 AutoMigrate 边界，`userauth` 自迁 `users` 和 token 记账幂等表，`all` 不再迁用户表
3. 清退 Gin 单体旧 user/auth DAO、model、service、router、middleware 和 JWT handler，并同步调整 agent/schedule/cache/outbox 相关调用依赖
4. 补齐 refresh token 防并发重放、MySQL 幂等 token 记账、额度 `>=` 拦截和 RPC 错误映射，避免重复记账与内部错误透出

文档：
1. 新增《学习计划论坛与Token商店PRD》

backend/services/userauth/rpc/handler.go

@@ -0,0 +1,177 @@
+package rpc
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"github.com/LoveLosita/smartflow/backend/respond"
+	"github.com/LoveLosita/smartflow/backend/services/userauth/rpc/pb"
+	userauthsv "github.com/LoveLosita/smartflow/backend/services/userauth/sv"
+	contracts "github.com/LoveLosita/smartflow/backend/shared/contracts/userauth"
+)
+
+type Handler struct {
+	pb.UnimplementedUserAuthServer
+	svc *userauthsv.Service
+}
+
+func NewHandler(svc *userauthsv.Service) *Handler {
+	return &Handler{svc: svc}
+}
+
+// Register 负责把 user/auth 的注册请求从 gRPC 协议转成内部服务调用。
+//
+// 职责边界：
+// 1. 只做 transport -> service 的参数搬运，不碰 DAO/Redis/JWT 细节；
+// 2. 业务错误统一转成 gRPC status，让 client 侧继续使用 `res, err :=`；
+// 3. 成功时只回传业务数据，不再在 payload 里塞 status/info。
+func (h *Handler) Register(ctx context.Context, req *pb.RegisterRequest) (*pb.RegisterResponse, error) {
+	if h == nil || h.svc == nil {
+		return nil, grpcErrorFromServiceError(errors.New("userauth service dependency not initialized"))
+	}
+	if req == nil {
+		return nil, grpcErrorFromServiceError(respond.MissingParam)
+	}
+
+	resp, err := h.svc.Register(ctx, contracts.RegisterRequest{
+		Username:    req.Username,
+		Password:    req.Password,
+		PhoneNumber: req.PhoneNumber,
+	})
+	if err != nil {
+		return nil, grpcErrorFromServiceError(err)
+	}
+	return &pb.RegisterResponse{Id: uint64(resp.ID)}, nil
+}
+
+func (h *Handler) Login(ctx context.Context, req *pb.LoginRequest) (*pb.TokensResponse, error) {
+	if h == nil || h.svc == nil {
+		return nil, grpcErrorFromServiceError(errors.New("userauth service dependency not initialized"))
+	}
+	if req == nil {
+		return nil, grpcErrorFromServiceError(respond.MissingParam)
+	}
+
+	resp, err := h.svc.Login(ctx, contracts.LoginRequest{
+		Username: req.Username,
+		Password: req.Password,
+	})
+	if err != nil {
+		return nil, grpcErrorFromServiceError(err)
+	}
+	return &pb.TokensResponse{
+		AccessToken:  resp.AccessToken,
+		RefreshToken: resp.RefreshToken,
+	}, nil
+}
+
+func (h *Handler) RefreshToken(ctx context.Context, req *pb.RefreshTokenRequest) (*pb.TokensResponse, error) {
+	if h == nil || h.svc == nil {
+		return nil, grpcErrorFromServiceError(errors.New("userauth service dependency not initialized"))
+	}
+	if req == nil {
+		return nil, grpcErrorFromServiceError(respond.MissingParam)
+	}
+
+	resp, err := h.svc.RefreshToken(ctx, contracts.RefreshTokenRequest{
+		RefreshToken: req.RefreshToken,
+	})
+	if err != nil {
+		return nil, grpcErrorFromServiceError(err)
+	}
+	return &pb.TokensResponse{
+		AccessToken:  resp.AccessToken,
+		RefreshToken: resp.RefreshToken,
+	}, nil
+}
+
+func (h *Handler) Logout(ctx context.Context, req *pb.LogoutRequest) (*pb.StatusResponse, error) {
+	if h == nil || h.svc == nil {
+		return nil, grpcErrorFromServiceError(errors.New("userauth service dependency not initialized"))
+	}
+	if req == nil {
+		return nil, grpcErrorFromServiceError(respond.MissingToken)
+	}
+
+	if err := h.svc.LogoutByAccessToken(ctx, req.AccessToken); err != nil {
+		return nil, grpcErrorFromServiceError(err)
+	}
+	return &pb.StatusResponse{}, nil
+}
+
+func (h *Handler) ValidateAccessToken(ctx context.Context, req *pb.ValidateAccessTokenRequest) (*pb.ValidateAccessTokenResponse, error) {
+	if h == nil || h.svc == nil {
+		return nil, grpcErrorFromServiceError(errors.New("userauth service dependency not initialized"))
+	}
+	if req == nil {
+		return nil, grpcErrorFromServiceError(respond.MissingToken)
+	}
+
+	resp, err := h.svc.ValidateAccessToken(ctx, contracts.ValidateAccessTokenRequest{
+		AccessToken: req.AccessToken,
+	})
+	if err != nil {
+		return nil, grpcErrorFromServiceError(err)
+	}
+	return &pb.ValidateAccessTokenResponse{
+		Valid:             resp.Valid,
+		UserId:            int64(resp.UserID),
+		TokenType:         resp.TokenType,
+		Jti:               resp.JTI,
+		ExpiresAtUnixNano: timeToUnixNano(resp.ExpiresAt),
+	}, nil
+}
+
+func (h *Handler) CheckTokenQuota(ctx context.Context, req *pb.CheckTokenQuotaRequest) (*pb.CheckTokenQuotaResponse, error) {
+	if h == nil || h.svc == nil {
+		return nil, grpcErrorFromServiceError(errors.New("userauth service dependency not initialized"))
+	}
+	if req == nil {
+		return nil, grpcErrorFromServiceError(respond.ErrUnauthorized)
+	}
+
+	resp, err := h.svc.CheckTokenQuota(ctx, contracts.CheckTokenQuotaRequest{
+		UserID: int(req.UserId),
+	})
+	if err != nil {
+		return nil, grpcErrorFromServiceError(err)
+	}
+	return &pb.CheckTokenQuotaResponse{
+		Allowed:             resp.Allowed,
+		TokenLimit:          int64(resp.TokenLimit),
+		TokenUsage:          int64(resp.TokenUsage),
+		LastResetAtUnixNano: timeToUnixNano(resp.LastResetAt),
+	}, nil
+}
+
+func (h *Handler) AdjustTokenUsage(ctx context.Context, req *pb.AdjustTokenUsageRequest) (*pb.CheckTokenQuotaResponse, error) {
+	if h == nil || h.svc == nil {
+		return nil, grpcErrorFromServiceError(errors.New("userauth service dependency not initialized"))
+	}
+	if req == nil {
+		return nil, grpcErrorFromServiceError(respond.MissingParam)
+	}
+
+	resp, err := h.svc.AdjustTokenUsage(ctx, contracts.AdjustTokenUsageRequest{
+		EventID:    req.EventId,
+		UserID:     int(req.UserId),
+		TokenDelta: int(req.TokenDelta),
+	})
+	if err != nil {
+		return nil, grpcErrorFromServiceError(err)
+	}
+	return &pb.CheckTokenQuotaResponse{
+		Allowed:             resp.Allowed,
+		TokenLimit:          int64(resp.TokenLimit),
+		TokenUsage:          int64(resp.TokenUsage),
+		LastResetAtUnixNano: timeToUnixNano(resp.LastResetAt),
+	}, nil
+}
+
+func timeToUnixNano(value time.Time) int64 {
+	if value.IsZero() {
+		return 0
+	}
+	return value.UnixNano()
+}