dudu MVP：五端语音输入法初始提交

- server：Go 网关（WS 流式识别中继/计费配额/微信登录支付 mock/反馈/埋点），gummy provider 已真实联调
- desktop：Tauri 2（全局快捷键 push-to-talk/浮层/托盘/设置/登录购买/反馈/首启引导）
- android：Compose 主 App + IME（键盘内录音直传）
- ios：App + 键盘扩展（1A spike 实证键盘内不可录音，走 deep link 听写）
- design/design-pipeline：设计系统 + token 导出 iOS/Android 主题
- doc：前后端设计文档（HTML）；web：官网宣传页；todo：任务看板

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

server/internal/user/handlers.go

@@ -0,0 +1,96 @@
+// Package user /v1/me 聚合、设备登记、应用更新检查。
+package user
+
+import (
+	"net/http"
+	"os"
+	"time"
+
+	"encoding/json"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+
+	"dudu/server/internal/auth"
+	"dudu/server/internal/quota"
+	"dudu/server/internal/store"
+	"dudu/server/pkg/protocol"
+)
+
+type Handlers struct {
+	DB    *gorm.DB
+	Quota *quota.Manager
+}
+
+// Me GET /v1/me（需登录）：余额/试用/账户态聚合 + 设备心跳登记。
+func (h *Handlers) Me(c *gin.Context) {
+	uid := auth.UserID(c)
+	var u store.User
+	if err := h.DB.First(&u, "id = ?", uid).Error; err != nil {
+		c.JSON(http.StatusUnauthorized, protocol.NewAPIError(protocol.ErrUnauthorized))
+		return
+	}
+	snap, err := h.Quota.Get(c, uid)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, protocol.NewAPIError(protocol.ErrInternal))
+		return
+	}
+	h.touchDevice(c, uid)
+
+	state := protocol.AccountOK
+	switch {
+	case snap.BalanceSeconds > 0:
+		state = protocol.AccountOK
+	case snap.TrialUsedToday < protocol.TrialDailySeconds:
+		state = protocol.AccountTrial
+	default:
+		state = protocol.AccountQuota
+	}
+	c.JSON(http.StatusOK, protocol.MeResponse{
+		UserID:          uid,
+		NicknameMasked:  auth.MaskNickname(u.Nickname),
+		BalanceSeconds:  snap.BalanceSeconds,
+		TrialDailyLimit: protocol.TrialDailySeconds,
+		TrialUsedToday:  snap.TrialUsedToday,
+		AccountState:    state,
+	})
+}
+
+// touchDevice 设备登记/心跳（X-Device-ID / X-Platform / X-App-Version 头）。
+func (h *Handlers) touchDevice(c *gin.Context, uid string) {
+	did := c.GetHeader("X-Device-ID")
+	if did == "" {
+		return
+	}
+	dev := store.Device{
+		ID: did, UserID: uid,
+		Platform: c.GetHeader("X-Platform"), AppVersion: c.GetHeader("X-App-Version"),
+		LastSeen: time.Now(),
+	}
+	_ = h.DB.Clauses(clause.OnConflict{
+		Columns:   []clause.Column{{Name: "id"}},
+		DoUpdates: clause.AssignmentColumns([]string{"user_id", "platform", "app_version", "last_seen"}),
+	}).Create(&dev).Error
+}
+
+// AppLatest GET /v1/app/latest?platform=mac|win|android|ios 🔓
+// 版本信息来自 APP_LATEST_JSON 环境变量（{"mac":{"version":...,"url":...},...}），
+// MVP 不建表；未配置平台返回 204。
+func (h *Handlers) AppLatest(c *gin.Context) {
+	raw := os.Getenv("APP_LATEST_JSON")
+	if raw == "" {
+		c.Status(http.StatusNoContent)
+		return
+	}
+	var all map[string]protocol.AppLatestResponse
+	if err := json.Unmarshal([]byte(raw), &all); err != nil {
+		c.Status(http.StatusNoContent)
+		return
+	}
+	if v, ok := all[c.Query("platform")]; ok {
+		c.JSON(http.StatusOK, v)
+		return
+	}
+	c.Status(http.StatusNoContent)
+}