feat(backend): implement task creation and admin web

backend-api/internal/domain/asset.go

@@ -0,0 +1,19 @@
+package domain
+
+import "time"
+
+const (
+	AssetPurposeTaskReference = "TASK_REFERENCE"
+	NormalizedImageMediaType  = "image/jpeg"
+)
+
+type Asset struct {
+	ID             string
+	CreatorSubject string
+	Purpose        string
+	MediaType      string
+	SizeBytes      int64
+	SHA256         string
+	StorageKey     string
+	CreatedAt      time.Time
+}