feat: added schemas for openapi (#452)

packages/api/src/schemas/attachment.ts

@@ -0,0 +1,12 @@
+import { z } from "zod";
+
+// ─── attachment.confirm ──────────────────────────────────────
+export const attachmentConfirmResponseSchema = z.object({
+  publicId: z.string(),
+  filename: z.string(),
+  originalFilename: z.string(),
+  contentType: z.string(),
+  size: z.number(),
+  s3Key: z.string(),
+  createdAt: z.date(),
+});