feat(api): add namespaces, batch ops, and admin logs

internal/model/namespace.go

@@ -0,0 +1,11 @@
+package model
+
+import "gorm.io/gorm"
+
+// Namespace represents a logical namespace for public models/bindings.
+type Namespace struct {
+	gorm.Model
+	Name        string `gorm:"size:100;uniqueIndex;not null" json:"name"`
+	Status      string `gorm:"size:50;default:'active'" json:"status"`
+	Description string `gorm:"size:255" json:"description"`
+}