模型定价: 悬空模型标记 + 一键清除 + 允许渠道只读

- 无渠道绑定的模型以「悬空」琥珀色徽标 + 卡片着色标记
- 新增「清除悬空」一键删除未绑定渠道的模型（DELETE /models/unused）
- 移除页面内「绑定渠道」弹窗与 chips 的解除按钮，渠道支持列表只在渠道抽屉管理
- 缺失提示带上渠道真实模型名（upstream_model）

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

server/internal/api/admin_models.go

@@ -45,19 +45,22 @@ func (h *Handler) AdminModels(c *gin.Context) {
 		})
 	}
 
-	// 渠道提供了但目录中缺失的模型（孤儿绑定，数据不一致时出现）
+	// 渠道选中但目录中缺失的模型（孤儿绑定：渠道绑定指向已被删除的模型）
 	var orphans []struct {
-		ChannelName string
-		ModelID     uint64
+		ChannelName   string
+		UpstreamModel string
+		ModelID       uint64
 	}
-	h.a.DB.Raw(`SELECT c.name as channel_name, b.model_id
+	h.a.DB.Raw(`SELECT c.name as channel_name, b.model_id, b.upstream_model
 		FROM channel_model_bindings b
 		LEFT JOIN models m ON m.id = b.model_id
 		LEFT JOIN channels c ON c.id = b.channel_id
 		WHERE m.id IS NULL`).Scan(&orphans)
 	missing := make([]gin.H, 0, len(orphans))
 	for _, o := range orphans {
-		missing = append(missing, gin.H{"channel": o.ChannelName, "model_id": o.ModelID})
+		missing = append(missing, gin.H{
+			"channel": o.ChannelName, "model_id": o.ModelID, "upstream_model": o.UpstreamModel,
+		})
 	}
 
 	// 在用但未定价的模型数（渠道已提供、需定价）
@@ -210,6 +213,29 @@ func (h *Handler) AdminDeleteModel(c *gin.Context) {
 	resp.OK(c, gin.H{"ok": true})
 }
 
+// AdminDeleteUnusedModels DELETE /api/v1/admin/models/unused — 一键清除未绑定任何渠道的模型。
+// 这些通常是渠道抽屉里选中过、后来又取消绑定留下的目录条目，客户端无法调用。
+func (h *Handler) AdminDeleteUnusedModels(c *gin.Context) {
+	var orphans []store.Model
+	if err := h.a.DB.Where("id NOT IN (SELECT DISTINCT model_id FROM channel_model_bindings)").Find(&orphans).Error; err != nil {
+		resp.Fail(c, http.StatusInternalServerError, "failed to load models")
+		return
+	}
+	names := make([]string, 0, len(orphans))
+	ids := make([]uint64, 0, len(orphans))
+	for _, m := range orphans {
+		names = append(names, m.Name)
+		ids = append(ids, m.ID)
+	}
+	if len(ids) > 0 {
+		if err := h.a.DB.Delete(&store.Model{}, ids).Error; err != nil {
+			resp.Fail(c, http.StatusInternalServerError, "failed to delete models")
+			return
+		}
+	}
+	resp.OK(c, gin.H{"deleted": names, "count": len(names)})
+}
+
 // AdminCreateModelBinding POST /api/v1/admin/models/:id/bindings
 func (h *Handler) AdminCreateModelBinding(c *gin.Context) {
 	modelID, err := strconv.ParseUint(c.Param("id"), 10, 64)