fix(stripe-plugin): convert refund amounts for zero-decimal currencies

[hayashi7752]

Problem

Refunds fail for zero-decimal currencies (JPY, KRW, …).

Vendure stores money amounts multiplied by 100, and the charge side already converts them for Stripe via getAmountInStripeMinorUnits (which divides by 100 for currencies without a fraction part). StripeService.createRefund, however, passes the raw Vendure amount straight to stripe.refunds.create, so a ¥1,300 refund (stored as 130000) is sent to Stripe as 130000 — 100x the real amount — and rejected:

StripeInvalidRequestError: Refund amount (¥130,000) is greater than charge amount (¥1,300)

This makes all refunds impossible on JPY stores (we hit this in production and have been running with a patched plugin since).

Fix

Apply the same currency check on the refund side so both directions stay symmetric with getAmountInStripeMinorUnits:

• export currencyHasFractionPart from stripe-utils.ts
• in createRefund, divide the amount by 100 for currencies without a fraction part

No behavior change for fractional currencies (USD, EUR, …).

Notes

• Same root cause family as the charge-side issue Stripe plugin sends incorrect amount for JPY vendure#1630, which introduced getAmountInStripeMinorUnits — the refund path was left unconverted.
• tsc -p tsconfig.build.json passes. Happy to add an e2e case for a zero-decimal channel if you'd like — let me know the preferred setup for switching the fixture currency.

🤖 Generated with Claude Code

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