refactor: 删除无用的模型展示名（display_name）字段

该字段仅存取、从不展示：管理列表只渲染 name，/v1/models 与用户侧
均不返回它。与渠道绑定 upstream_model 的名字映射职责重叠且悬空。
- store.Model 结构体、admin CRUD、seed 数据移除 display_name
- 前端编辑弹窗输入框、表单状态、types.ts 同步移除
- 本地库已 ALTER TABLE DROP COLUMN；生产残留列无害

server/internal/api/admin_channel_models.go

@@ -118,7 +118,7 @@ func (h *Handler) AdminChannelAddModel(c *gin.Context) {
 	// 解析或创建全局模型（客户端名）
 	var m store.Model
 	if err := h.a.DB.Where("name = ?", globalName).First(&m).Error; err != nil {
-		m = store.Model{Name: globalName, DisplayName: globalName, Enabled: true}
+		m = store.Model{Name: globalName, Enabled: true}
 		if err := h.a.DB.Create(&m).Error; err != nil {
 			resp.Fail(c, http.StatusInternalServerError, "failed to create model")
 			return

server/internal/api/admin_models.go

@@ -41,7 +41,7 @@ func (h *Handler) AdminModels(c *gin.Context) {
 		needsPricing := used && m.InputPrice == 0 && m.OutputPrice == 0 && m.CacheReadPrice == 0
 		denied := containsStr(deny, m.Name) || (len(allow) > 0 && !containsStr(allow, m.Name))
 		out = append(out, gin.H{
-			"id": m.ID, "name": m.Name, "display_name": m.DisplayName,
+			"id": m.ID, "name": m.Name,
 			"input_price": m.InputPrice, "output_price": m.OutputPrice, "cache_read_price": m.CacheReadPrice,
 			"enabled": m.Enabled, "sort": m.Sort, "channels": chs,
 			"used": used, "needs_pricing": needsPricing, "denied": denied,
@@ -119,7 +119,6 @@ func containsStr(list []string, s string) bool {
 func (h *Handler) AdminCreateModel(c *gin.Context) {
 	var req struct {
 		Name           string  `json:"name" binding:"required,min=1,max=128"`
-		DisplayName    string  `json:"display_name"`
 		InputPrice     float64 `json:"input_price"`
 		OutputPrice    float64 `json:"output_price"`
 		CacheReadPrice float64 `json:"cache_read_price"`
@@ -130,13 +129,10 @@ func (h *Handler) AdminCreateModel(c *gin.Context) {
 		return
 	}
 	m := store.Model{
-		Name: req.Name, DisplayName: req.DisplayName,
+		Name: req.Name,
 		InputPrice: req.InputPrice, OutputPrice: req.OutputPrice, CacheReadPrice: req.CacheReadPrice,
 		Enabled: boolOr(req.Enabled, true),
 	}
-	if m.DisplayName == "" {
-		m.DisplayName = m.Name
-	}
 	if err := h.a.DB.Create(&m).Error; err != nil {
 		resp.Fail(c, http.StatusConflict, "failed to create model (name may already exist)")
 		return
@@ -144,7 +140,7 @@ func (h *Handler) AdminCreateModel(c *gin.Context) {
 	resp.Created(c, gin.H{"id": m.ID, "name": m.Name})
 }
 
-// AdminUpdateModel PUT /api/v1/admin/models/:id — 价格/展示名/启停/排序。
+// AdminUpdateModel PUT /api/v1/admin/models/:id — 价格/启停/排序。
 func (h *Handler) AdminUpdateModel(c *gin.Context) {
 	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
 	if err != nil {
@@ -152,7 +148,6 @@ func (h *Handler) AdminUpdateModel(c *gin.Context) {
 		return
 	}
 	var req struct {
-		DisplayName    *string  `json:"display_name"`
 		InputPrice     *float64 `json:"input_price"`
 		OutputPrice    *float64 `json:"output_price"`
 		CacheReadPrice *float64 `json:"cache_read_price"`
@@ -169,9 +164,6 @@ func (h *Handler) AdminUpdateModel(c *gin.Context) {
 		return
 	}
 	updates := map[string]any{}
-	if req.DisplayName != nil {
-		updates["display_name"] = *req.DisplayName
-	}
 	if req.InputPrice != nil {
 		updates["input_price"] = *req.InputPrice
 	}