feat(buy-crypto): send a KYC-limit refusal to TransFi's verification page

[mul53]

Summary

When an order goes over the limits of the user's current TransFi KYC level, the backend returns STANDARD_KYC_REQUIRED or ENHANCED_KYC_REQUIRED with action: complete_kyc. The error screen answered that with Verify identity, which opened our own identity check (Sumsub or Didit). The user is already verified there, so:

1. The backend refused a new session (409).
2. The app reopened the buy-crypto pending step.
3. That step saw ready and went straight to the amount screen.
4. The user placed the order again and got the same refusal.

This PR sends these users to TransFi's own verification page instead.

Changes

For the two limit codes only:

• Title: "Upgrade your verification". The message comes from the backend: "Please upgrade your KYC to make further purchases."
• Verify identity: calls the new POST /transfi/kyc/upgrade for the level the refusal names (standard or advanced), then opens TransFi's page. It opens the same way as the hosted retry: openBrowserAsync on native, and window.open on web with a fallback button when a popup blocker stops it.
• Already submitted: if TransFi is already reviewing a submission, the screen shows "Verification in review" and hides the button.
• Buy a smaller amount: a new second button that goes back to the amount screen, since the limit only caps this purchase.
• Failures:
  • A transient one (TransFi down, dropped connection) shows an inline message and keeps the button.
  • A refusal with its own verdict (account barred, no TransFi profile) replaces the screen's error.

Every other complete_kyc error, such as a user with no verification, behaves exactly as before.

Testing

• New tests: components/BuyCrypto/Transfi/__tests__/transfiErrorUpgrade.test.tsx (8 tests) and new cases in lib/__tests__/transfiErrors.test.ts.
• Full suite: npx jest passes, 134 suites and 1,558 tests.
• Typecheck: npx tsc --noEmit shows no errors in changed files. It reports 9 errors elsewhere (app/, BankTransfer, CardBanner, the bridge hooks and others), all in files this PR doesn't touch.
• Lint: ESLint and Prettier are clean on changed files.

Depends on

Backend PR: https://github.com/Solid-Money/solid-backend/pull/1880. It adds POST /transfi/kyc/upgrade and the new copy, and should deploy first.

🤖 Generated with Claude Code

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2 Skipped Deployments

Project	Deployment	Actions	Updated
solid-app	Ignored		Sep 28, 2026 8:48pm UTC
solid-app-staging	Ignored		Sep 28, 2026 8:48pm UTC

[claude]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.