Align backend workbench API with prototype

backend/internal/models/project_channel.go

@@ -0,0 +1,20 @@
+package models
+
+import "time"
+
+type SenlinAgentProjectChannel struct {
+	ID              uint   `gorm:"primaryKey"`
+	Identity        string `gorm:"type:char(36);uniqueIndex"`
+	ProjectID       uint   `gorm:"index;not null"`
+	ProjectIdentity string `gorm:"type:char(36);index"`
+	Title           string `gorm:"not null"`
+	Icon            string `gorm:"not null;default:link"`
+	URL             string `gorm:"not null"`
+	SortOrder       int    `gorm:"not null;default:0"`
+	CreatedAt       time.Time
+	UpdatedAt       time.Time
+}
+
+func (SenlinAgentProjectChannel) TableName() string {
+	return "senlin_agent_project_channels"
+}