basic file sharing

frontend/lib/schemas/share.ts

@@ -0,0 +1,12 @@
+import { number, object, string } from 'yup';
+
+export const shareSchema = object({
+    password: string()
+        .trim()
+        .transform((s: string) => (s.length > 0 ? s : undefined))
+        .optional(),
+    lifetime: number()
+        .positive()
+        .transform((n) => (isNaN(n) ? undefined : n))
+        .optional(),
+});