feat: add asset variants endpoint

apps/web/app/api/assets/[id]/variants/shape.ts

@@ -0,0 +1,19 @@
+type VariantRow = {
+  kind: string;
+  size: number;
+  key: string;
+};
+
+type VariantShape = {
+  kind: string;
+  size: number;
+  key: string;
+};
+
+export function shapeVariants(rows: VariantRow[]): VariantShape[] {
+  return rows.map((row) => ({
+    kind: row.kind,
+    size: row.size,
+    key: row.key,
+  }));
+}