The clean clone builds, formats and tests green with no stray .gitmodules. The work is complete and committed.

Delivered

A standalone Foundry project at the repository root, committed as b92a557.

• Contracts in src/. RentalEscrow is the deposit escrow. MockPaymentToken is the kkk / dds token with 6 decimals and a fixed 1,000,000 supply minted to a constructor-supplied holder.
• Tests in test/. 47 unit tests, 9 fuzz tests, 8 stateful invariants driven by a handler, plus token and script tests. All 64 pass under the verifier's fuzz seed.
• Scripts in script/. An env-driven deploy and seed script whose logic the tests call directly, and demo.sh, which walks the full flow on Anvil with cast.
• Docs. README.md covers setup, commands, deployment parameters, operational duties, trust assumptions and limitations. docs/INTEGRATION.md gives the events, ABI surface and the uncertain-outcome recovery procedure for the UI and backend. docs/TEST-RESULTS.md records the results obtained here.
• Dependencies vendored as plain files: forge-std v1.9.7 and OpenZeppelin v5.1.0. The compiler is pinned to 0.8.26, ffi and filesystem access are off.

Design points worth knowing

• Idempotency is a caller-chosen clientRef on reserve, unique per renter. A replay reverts with an error that carries the existing reservation id, and the backend can resolve any unknown outcome with one view call.
• Policy snapshots store deposit, fee, policy id and expiry on each reservation. Callers pass the policy id they quoted, so an admin change between quote and inclusion reverts instead of silently charging a different deposit.
• Accounting. Escrowed deposits plus refund credits plus accrued fees are tracked separately and the admin can only withdraw from accrued fees. The invariant suite asserts the balance equals these liabilities and that ghost totals of deposits in equal payouts plus liabilities.
• Exact boundary. At the expiry timestamp cancel and checkout revert and expire succeeds. Rented items never expire.

Verification performed

• forge build, forge test with the verifier's seed, and forge fmt --check all pass, both in the working tree and in a fresh clone.
• The Anvil demo ran end to end, with retries, competing reservations, over-withdrawals and double refunds all rejected as expected.
• Five bugs injected one at a time into the escrow were each caught by the suites. I also found that handler assertions were silently swallowed under the default invariant config, so fail_on_revert is pinned to true and the handler catches every legitimate revert itself.

Not run

Slither and Mythril are not installed here, and no long fuzz campaign or public deployment was done. Both are noted in the README and results document. One environment note: the sandbox pins any .gitmodules path read-only, so OpenZeppelin's own copy could not be deleted from disk. It is excluded via .gitignore and is absent from the commit.