fix(wallet): select first supported OID4VCI credential format to avoid unsupported issuance requests

[darshit2308]

Description:
The wallet was not filtering offered credentials by supported format before requesting issuance.
If an issuer offered an unsupported format (e.g., AnonCreds or jwt_vc) first in the credential
offer list, the wallet would blindly attempt to request it and crash at runtime with an unhelpful
error, violating the OID4VCI specification's expectation that holders negotiate supported formats.

• Add WALLET_SUPPORTED_CREDENTIAL_FORMATS constant listing the four wallet-supported formats (vc+sd-jwt, jwt_vc_json, jwt_vc_json-ld, mso_mdoc)
• Add walletSupportsCredentialFormat helper that safely handles undefined format values
• Replace naive offeredCredentials[0] selection with .find() that filters by supported format
• Add early validation guard when a specific credentialConfigurationIdToRequest is passed but resolves to an unsupported format
• Add descriptive error messages showing both supported and offered formats to aid debugging

Related issue(s):
No prior issue, this is a self-contained bug fix identified during code review of the OID4VCI
credential handling flow in useOpenIdHandlers.ts.

Notes for reviewer:
The core change is in receiveCredentialFromOpenId4VciOffer inside useOpenIdHandlers.ts.
Previously, offeredCredentials[0] was used without any format check. Now:

• When no specific credential config ID is requested, the wallet picks the first credential whose format it supports
• When a specific config ID is requested, the wallet also validates the resolved credential's format is supported before proceeding
• Both failure paths produce actionable error messages listing supported vs offered formats
• No behavior change occurs when the issuer only offers supported formats (the common case)

Checklist

• Documented (Code comments added explaining the format filtering logic)
• Tested (Three new tests added to useOpenIdHandlers.spec.ts covering: format-aware selection from mixed offers, explicit unsupported format rejection, and all-unsupported-formats rejection)

[Copilot]

Pull request overview

Fixes the OID4VCI issuance flow in the wallet by ensuring the requested credential configuration is selected based on a format the wallet supports, preventing runtime crashes when issuers list unsupported formats first.

Changes:

• Introduces a wallet-scoped allowlist of supported credential formats plus a helper to validate formats (including undefined).
• Updates credential selection to choose the first supported offered credential when no specific configuration ID is provided, and validates explicitly requested IDs for supported format.
• Adds tests covering mixed-format offers, explicit unsupported-format rejection, and all-unsupported rejection.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
heka-wallet/app/src/credentials/useOpenIdHandlers.ts	Adds supported-format filtering/validation and improves failure behavior with more descriptive errors.
heka-wallet/app/__tests__/credentials/useOpenIdHandlers.spec.ts	Adds regression tests ensuring selection/validation behaves correctly with unsupported formats.

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[AlexanderShenshin]

Thanks for a contribution!
Looks great, I have couple of minor suggestions here.

[darshit2308]

@AlexanderShenshin Sure, I have made the required changes .