feat(ECR-011): 昵称、首页贴士与档案 Self 唯一/合盘交叉校验

每账号仅一条 self（migration 40902）；合盘只选 TA；账号昵称可改；首页穿衣/颜色/养生贴士。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/internal/handler/auth.go

@@ -23,6 +23,7 @@ func (h *AuthHandler) Register(api *gin.RouterGroup) {
 	g.POST("/login", h.Login)
 	g.POST("/logout", h.Logout)
 	g.GET("/me", h.Me)
+	g.PATCH("/me", h.PatchMe)
 }
 
 type authBody struct {
@@ -97,6 +98,30 @@ func (h *AuthHandler) Me(c *gin.Context) {
 	response.OK(c, me)
 }
 
+type patchMeBody struct {
+	Nickname string `json:"nickname"`
+}
+
+// PatchMe handles PATCH /auth/me (update nickname).
+func (h *AuthHandler) PatchMe(c *gin.Context) {
+	userID, ok := middleware.UserIDFromContext(c)
+	if !ok {
+		response.Fail(c, http.StatusUnauthorized, 40100, "unauthorized")
+		return
+	}
+	var body patchMeBody
+	if err := c.ShouldBindJSON(&body); err != nil {
+		response.Fail(c, http.StatusBadRequest, 10000, "invalid request")
+		return
+	}
+	me, err := h.Svc.UpdateNickname(c.Request.Context(), userID, body.Nickname)
+	if err != nil {
+		response.Fail(c, http.StatusBadRequest, 40113, err.Error())
+		return
+	}
+	response.OK(c, me)
+}
+
 func bearerToken(c *gin.Context) string {
 	h := c.GetHeader("Authorization")
 	if strings.HasPrefix(strings.ToLower(h), "bearer ") {