Add stable pagination cursor to get_blacklist via get_blacklist_page hardening

[thlpkee20-wq]

Description

get_blacklist returns the entire blacklist for a token in one call, which can exceed gas limits for large lists and is also embedded into report_revenue events. Promote get_blacklist_page as the primary read path with a documented deterministic cursor and a hard cap, and have internal snapshots use a bounded form.

Requirements and context

• Must be secure, tested, and documented
• Should be efficient and easy to review
• Relevant code: src/lib.rs (get_blacklist, get_blacklist_page, get_blacklist_size, report_revenue)
• Ordering must remain insertion order and deterministic

Suggested execution

• Fork the repo and create a branch
• git checkout -b feat/blacklist-pagination-hardening
• Implement changes
  • Cap get_blacklist_page limit at MAX_PAGE_LIMIT and return next_cursor
  • Document that get_blacklist is bounded/legacy and prefer the paged form off-chain
  • Ensure report_revenue snapshot uses a bounded read to avoid unbounded event payloads
• Validate security and correctness assumptions

Test and commit

• Run tests
  • cargo test
• Cover edge cases
  • Empty blacklist, single page, multi-page, cursor exhaustion, over-cap limit
• Include test output and security notes

Example commit message

feat: harden blacklist pagination and bound event snapshots

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours

[millicentogalanya]

@millicentogalanya has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

please assign this issue to me, i've worked on something similar and i'll deliver quickly. ETA~4hrs

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

[drips-wave]

Congratulations, @millicentogalanya! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @millicentogalanya: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

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