chore: remove 'minBalanceUSD' from eligibility response

[lwin-kyaw]

Explanation

This PR removes minBalanceUSD from eligibility response.

References

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Remove minBalanceUSD from subscription eligibility and update related tests/mocks.

• Types:
  • Remove minBalanceUSD from SubscriptionEligibility in packages/subscription-controller/src/types.ts.
• Tests:
  • Update mocks and expectations in packages/subscription-controller/src/SubscriptionController.test.ts and packages/subscription-controller/src/SubscriptionService.test.ts to drop minBalanceUSD from eligibility payloads and defaults.

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