test(frontend): add contract-driven tests for transfer, quote, and error states

[arisu6804]

Problem

Schema or precision changes can silently break the send flow or misrepresent transfer outcomes.

Objective

Deliver a production-quality improvement to API adapters, send flow, and receipt screens that creates measurable value for correctness, security, reliability, performance, or maintainability.

Implementation scope

• Maintain versioned fixtures for quotes, validation, authorization, pending, settled, failed, and expired states; assert safe numeric parsing.

Acceptance criteria

• Breaking response changes fail with actionable diffs; all supported states render correctly; tests are deterministic without live providers.

Required validation

• Contract fixture, component, error-state, precision, and deterministic integration tests.
• Existing tests and CI remain passing.
• Add regression coverage for the original failure mode.
• Do not weaken, delete, or skip unrelated tests to obtain a green build.

PR quality bar

• Keep the PR focused and explain design tradeoffs, compatibility impact, and test evidence.
• Avoid typo-only, documentation-only, cosmetic-only, or unrelated refactor submissions.

Out of scope

• Broad rewrites not required by the acceptance criteria.
• Changes to unrelated services, contracts, or user flows.

[Ayom04]

I will like to work on this.

[grantfox-oss]

🦊 GrantFox — @Ayom04 has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #282)
2. Your PR will be reviewed by the RemitFlow maintainers

Good luck! Track your progress on GrantFox.