feat: changed update intent callback return signature

[sakksham7]

Type of Change

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

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Description

Updated the updateIntent function signature across Context.res and OrcaJs.res to accept a callback typed as unit => promise<JSON.t> instead of unit => promise<string>, aligning the API contract with the expected behavior.
Changed in:

• Context.res: elementsType.updateIntent and paymentSessionContextType.updateIntent
• OrcaJs.res: element.updateIntent and initPaymentSession.updateIntent

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How did you test it?

• Ran npm run re:build — no build artifact changes, confirming this is a compile-time only change with no runtime impact.
• Verified updated signature is consistent across all four updateIntent usages.

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Usage Notes

• No impact on JavaScript consumers — types are erased at compile time and the JS output is identical.
• ReScript consumers must update updateIntent callbacks from unit => promise<string> to unit => promise<JSON.t> to comply with the updated contract.
• No backward compatibility guaranteed for ReScript consumers.

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Version Update

• I have bumped the package version in package.json following semantic versioning:
  • x.x.x for major changes (breaking).
  • 2.3.0 for minor changes (new feature, no breaking changes).
  • x.x.x for patch changes (bug fixes, minor improvements).

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Checklist

• I ran npm run re:build and verified the build artifacts.
• I reviewed the code for style, readability, and consistency.
• I verified the changes are backward compatible (if applicable).
• I tested this change in a real or simulated consuming project.
• I updated documentation, README, or usage examples if necessary.

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Screenshots or Logs

No runtime changes — build output is identical before and after. API contract update is compile-time only.