渠道: 支持手工录入模型(无 /models) + 模型映射自定义名称

- AdminChannelAddModel 改为 upstream_model + custom_name:
  无 /models 接口的渠道直接填上游模型名, 可选自定义名作为客户端调用名,
  全局模型不存在时自动创建
- "支持的模型"弹窗: 手工添加 + 建议下拉(自建,紧贴输入框)/水平排列/交换位置
- 网关仍按绑定映射改写请求 model 字段

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

server/internal/api/admin_channel_models.go

@@ -31,7 +31,8 @@ func (h *Handler) AdminChannelModels(c *gin.Context) {
 	resp.OK(c, gin.H{"items": out})
 }
 
-// AdminChannelAddModel POST /api/v1/admin/channels/:id/models — 绑定模型到渠道。
+// AdminChannelAddModel POST /api/v1/admin/channels/:id/models — 手工添加渠道支持的模型。
+// 无需渠道具备 /v1/models 接口：直接填上游模型名，可选自定义名称作为客户端调用名。
 func (h *Handler) AdminChannelAddModel(c *gin.Context) {
 	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
 	if err != nil {
@@ -39,31 +40,35 @@ func (h *Handler) AdminChannelAddModel(c *gin.Context) {
 		return
 	}
 	var req struct {
-		ModelName     string `json:"model_name" binding:"required"`
-		UpstreamModel string `json:"upstream_model"`
+		UpstreamModel string `json:"upstream_model" binding:"required"` // 渠道侧真实模型名
+		CustomName    string `json:"custom_name"`                      // 客户端调用名，空=用上游名
 		Weight        *int   `json:"weight"`
 	}
 	if err := c.ShouldBindJSON(&req); err != nil {
 		resp.Fail(c, http.StatusBadRequest, "invalid input")
 		return
 	}
-	var m store.Model
-	if err := h.a.DB.Where("name = ?", req.ModelName).First(&m).Error; err != nil {
-		resp.Fail(c, http.StatusNotFound, "model not found")
-		return
+	globalName := req.CustomName
+	if globalName == "" {
+		globalName = req.UpstreamModel
 	}
-	upstream := req.UpstreamModel
-	if upstream == "" {
-		upstream = m.Name
+	// 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}
+		if err := h.a.DB.Create(&m).Error; err != nil {
+			resp.Fail(c, http.StatusInternalServerError, "failed to create model")
+			return
+		}
 	}
 	b := store.ChannelModelBinding{
-		ChannelID: id, ModelID: m.ID, UpstreamModel: upstream, Weight: intOr(req.Weight, 1),
+		ChannelID: id, ModelID: m.ID, UpstreamModel: req.UpstreamModel, Weight: intOr(req.Weight, 1),
 	}
 	if err := h.a.DB.Create(&b).Error; err != nil {
 		resp.Fail(c, http.StatusConflict, "binding may already exist")
 		return
 	}
-	resp.Created(c, gin.H{"id": b.ID, "model_id": m.ID, "model_name": m.Name, "upstream_model": upstream, "weight": b.Weight})
+	resp.Created(c, gin.H{"id": b.ID, "model_id": m.ID, "model_name": m.Name, "upstream_model": req.UpstreamModel, "weight": b.Weight})
 }
 
 // AdminChannelUpdateModel PATCH /api/v1/admin/channels/:id/models/:bid — 改映射名/权重。