Build invoice payment retry budget manager

[Kingsman-99]

Label: complexity: high
Points: 200

Description

src/retryEngine.ts's RetryEngine retries per-call; for a payer making many payments in a session, an overall retry "budget" prevents one degraded period from exhausting excessive total retry time across all calls combined.

Technical Context

New src/retryBudget.ts. Tracks cumulative retry time/count across calls sharing a RetryEngine instance; once budget exhausted, subsequent calls fail fast without retrying until the budget window resets.

Acceptance Criteria

• RetryBudget.consume(retryDurationMs) / .hasRemaining(): boolean / resets on a rolling window
• RetryEngine (existing) accepts an optional shared RetryBudget and checks it before each retry attempt
• Tests: budget exhaustion stops further retries; window reset restores budget

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[ppaker119]

@ppaker119 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi maintainer. I am interested in this issue.

I have experience working across frontend, backend, smart contracts, and developer tooling, and I’m comfortable making targeted fixes and improvements in existing codebases. I’ll ensure the implementation is clean, tested, and aligned with the project requirements.

Thanks!

ℹ️ Repo Maintainers: To accept this application, review their application or assign @ppaker119 to this issue.