dashboard: Add unit tests for API client error handling and token refresh

[ONEONUORA]

Description

Verify HTTP 401 response triggers token refresh logic in API utility.

Files to Edit/Create

• dashboard/lib/api.ts

Acceptance Criteria

• Mock fetch returning 401, verify refresh endpoint called, and assert original request retried.

Guidance / Hints

Intercept fetch calls.

[Marvelg256]

@Marvelg256 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi Maintainer! I'd like to work on this issue. I'm confident I can complete it and submit a PR within 24 hours. Looking forward to contributing!

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[Samuelaladesiun3334]

@Samuelaladesiun3334 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Please i would love to work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Samuelaladesiun3334 to this issue.

[CodeNinjaStephen]

@CodeNinjaStephen has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello maintainer, im interested in this issue and I’ll appreciate the opportunity to work on it as soon as possible

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