fix: payload optional processing_account_id validations

[susrithasabbini]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

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Description

Fix validation logic for multi-currency auth key configuration.

Each currency configuration contains:

• api_key (required)
• processing_account_id (optional)

Previously, the Proceed button was enabled even when the request payload was invalid.
For example, if api_key was filled in one currency and only processing_account_id
(optional field) was filled in another currency, the button was enabled, which should
not be allowed.

The Proceed button should be enabled only when the request dictionary is valid.

Validation rules

• If any optional field is filled for a currency, all required fields for that
  currency must also be filled
• The request is considered valid only if at least one required field is filled
  across all currencies
• If nothing is filled for any currency, the request is invalid

Scenarios

Scenario	Result
Nothing filled anywhere	false
Required filled in any country	true
Optional filled but required missing	false
Required + optional	true

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Motivation and Context

Fixes: https://github.com/juspay/hyperswitch-cloud/issues/14135

This change ensures that invalid payloads are not allowed to proceed and that
currency-wise validation is enforced correctly.

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How did you test it?

Tested locally by validating different combinations of required and optional
fields across multiple currencies.

Screen.Recording.2026-01-22.at.3.50.24.PM.mov

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Where to test it?

• INTEG
• SANDBOX
• PROD

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Checklist

• I ran npm run re:build
• I reviewed the submitted code
• I added unit tests for my changes where possible

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