refactor(documents): split document models

backend/internal/models/document_blob.go

@@ -0,0 +1,18 @@
+package models
+
+import "time"
+
+type SaDocumentBlob struct {
+	ID           uint   `gorm:"primaryKey"`
+	DocumentID   uint   `gorm:"uniqueIndex;not null"`
+	StorageKey   string `gorm:"size:64;uniqueIndex;not null"`
+	RelativePath string `gorm:"not null"`
+	OriginalName string `gorm:"not null"`
+	Checksum     string `gorm:"size:64;not null"`
+	CreatedAt    time.Time
+	UpdatedAt    time.Time
+}
+
+func (SaDocumentBlob) TableName() string {
+	return "sa_document_blobs"
+}