Created launch.json matching LaunchToken, Guestbook($token), and the native-ETH pool settings.

Schema and constructor ABI checks passed. forge build succeeded; all 45 tests passed, including protected checks.

Only launch.json is changed for submission.

The review is complete. No defects were found in the Access Control, Trust Gap, or Asymmetry areas, and the findings file records a clean result with full coverage.

Outcome. The findings file at the repository root holds an empty findings list and nine coverage rows. All four listed entry points are marked holds, plus rows for the constructor, two invariants, and the two static-analysis leads. No source or test files were changed. The scratch probe directory was deleted after its tests passed.

What I checked, by guide.

• Access Control. The guestbook has no owner, initializer, setter, sweep, pause, or upgrade path. The only state-writing function is sign, which is permissionless by design. It pulls from msg.sender only, so no caller can spend another account's approval, including an infinite one. The constructor reads code size and decimals and grants nothing. The token is unmodified OpenZeppelin v5.0.2 with a fixed supply.
• Asymmetry. The stored entry, the emitted event, and the returned index carry identical values. The long-message revert path leaves no partial state. The exact-delta burn check reads the same slot before and after and cannot be perturbed by a third party under the real token, because plain ERC-20 transfers have no hooks.
• Trust Gap. There is no privileged actor to combine with economics or asymmetry. Payment flows directly from signer to the dead address and the contract never holds custody.

Static-analysis leads. The reentrancy lines are not defects: the real token has no callbacks, the nonReentrant guard rejects re-entry with a hooking token, and no second state-writing function exists for cross-function re-entry. The unchecked ETH send line is a false positive, since sign is non-payable and sends no ETH.

Verification run. The existing suite of 37 tests passed, including the fuzz and invariant suites. Three scratch probes confirmed infinite-approval isolation, exact-delta behaviour across repeated donations to the dead address, and zero contract custody. All passed before I removed them.

Not reached. Nothing within the assigned area was left unchecked. Math, oracle, and upgradeability guides do not apply to this code and were not run as separate passes.

The review is complete. No defects were found in the Math Precision, Boundary or Numerical Gap areas, and the findings file records an empty list with full coverage of all four entry points.

What I checked in the guestbook's sign path

• Math. The ten-token cost is a constant scaled to 18 decimals, and the constructor refuses any token whose decimals() is not 18, so there is no scale mismatch. The only arithmetic is the checked addition in the burn-delta check. I confirmed it cannot overflow by pre-sending the whole supply to the burn address and signing once more. There are no divisions, casts or unchecked blocks.
• Boundaries. The 280-byte limit is inclusive, matching the brief. Existing tests cover 280, 281 and a 284-byte multi-byte string, plus a fuzz on both sides. Empty messages are allowed and charged. Index assignment and the out-of-range read revert are correct, including at the maximum index. Timestamps at zero and at the 64-bit maximum round-trip as stored.
• External-call corners. The token address is immutable and checked for code and decimals at construction. A contract with code but no decimals() fails deployment loudly. SafeERC20 plus the exact balance-delta check rejects fee-on-transfer, false-return, silent no-op and reverting tokens, as the adversarial suite demonstrates. The burn address signing for itself is correctly rejected because a self-transfer produces no delta.
• Static analysis leads. The Slither and Aderyn reentrancy lines point at state writes after the token call. The reentrancy guard covers them and the launch token has no hooks, so I did not promote them.

Token and dependencies. The vendored OpenZeppelin v5.0.2 ERC20, SafeERC20 and ReentrancyGuard sources are unmodified. The fixed supply fits comfortably in uint256, infinite allowances keep standard semantics, and the project test suite passes with 37 tests including the stateful invariant run.

The scratch tests I wrote to confirm these edges have been removed, and the tree contains only the findings file.

Saved review results: no substantiated defects; all four entry points covered.

Passed 37 project tests and eight protected checks using local deployment inputs, including 4,096 invariant calls. Source and configuration files remain unchanged.

The review is complete. The findings file is written and the scratch tests are removed.

Result: no substantiated defects in the Economic Security, Invariant or Flow Gap areas. .imd-findings.json holds an empty findings list and a 12-row coverage record covering all four entry points plus the invariants and static-analysis leads I checked.

What I verified against the guides

• Payment flow in sign. The length check, the before/after balance read around safeTransferFrom, the exact-receipt check, and the reentrancy guard mean no path appends an unpaid entry or charges anyone other than the caller. A relayer cannot spend an approver's allowance.
• Conservation. Across the existing stateful invariant and a 500-entry scratch run, the dead-address balance equals entries times ten tokens, the guestbook never holds tokens, and total supply stays fixed.
• Griefing. A third party transferring to the dead address in the same block does not break the exact-receipt check, since both balance reads happen inside one call with no token hook between them. Per-sign gas is flat as the book grows.
• Static-analysis leads. The Slither and Aderyn reentrancy lines are not reproducible as harm: the launch token has no hooks, the guard covers the only state-changing function, and the existing adversarial mock tests already show reentry cannot append an entry. The "ETH sent without address check" line is a false positive, since the contract has no payable path at all.
• Deployment. The constructor is nonpayable, ignores msg.sender, moves no supply, and dependencies are vendored as plain files with no submodule.

Documented design points, not defects. Burning is a transfer to the dead address so total supply does not fall, and tokens sent directly to the guestbook are unrecoverable. Both are stated in the README and match the brief's wording.

Everything in my area was reached within budget. Nothing is left for a follow-up pass.

Added boundary, failure-path, rollback, fuzz, and stateful invariant tests under test/.

forge build and forge test pass: 51 passed, 0 failed, including 16,384 randomized invariant calls.

Only test/ changed. No implementation defects found.

Wrote .imd-findings.json with no substantiated defects and coverage of all four entry points.

51 project tests and 8 protected checks passed offline. Source and configuration files remain unchanged.