bug(ack-pay): paymentOptionSchema accepts an empty network string #219

Summary

paymentOptionSchema treats network as optional, but when the field is present both schemas still accept an empty string:

• valibot: network: v.optional(v.string())
• zod: network: z.string().optional()

So { ..., network: "" } parses successfully. An empty network is not a meaningful CAIP / chain hint; it is the same class of empty-field hole that #183 covers for id / currency / recipient, just on the optional field.

Affected files

• packages/ack-pay/src/schemas/valibot.ts
• packages/ack-pay/src/schemas/zod.ts

Expected

If network is present, require a non-empty string (same nonEmptyString / min(1) shape as the other identifier fields). Omitting the field remains valid.

AI usage

Filed with Cursor assistance while scanning for schema gaps not covered by open PRs. I reviewed the schema lines above and take responsibility for the report.