Closes #542

[mansur-codes]

closes #542

Adds a write rate limit to price_registry.rs so admins can't spam price updates faster than the configured cooldown. The limit kicks in after the first write; subsequent writes check the ledger sequence gap against PRICE_WRITE_RATE_LIMIT and reject with WriteRateLimitExceeded if it's too soon.

What changed

price_registry.rs holds the core logic: set_price now reads PriceRegistryLastWrite from storage before writing, computes the sequence delta, and short-circuits if the gap is under the threshold. First write skips the check. get_price and remove_price are unchanged functionally; remove_price clears the last-write entry alongside the price itself so a removal doesn't ghost-lock the registry.

The other files were mostly cleanup that the implementation forced: duplicate SettlementError, StorageKey, and Price variants scattered across lib.rs, errors.rs, and types.rs got consolidated. ClaimSimulation was missing from types.rs entirely. lib.rs now exposes the three entrypoints via pub mod price_registry instead of inlining them.

Tests

All rate-limit behaviour is covered in price_registry.rs: first write allowed, second write within cooldown rejected, write after cooldown passes, and the sequence-number edge at exactly the boundary. 126 tests pass. The 17 failures are pre-existing and unrelated to this issue; 16 are test_ttl_bump variants blocked by soroban-sdk's newer contract-context restriction on extend_ttl(), and one is a Wasm-hash issue in test_upgrade_emits_upgraded_event.

Notes

require_auth is on every state-changing entrypoint. Math is overflow-safe throughout. No unwrap() in production paths.

[drips-wave]

@mansur-codes Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits