The Counter project is complete, verified, and committed as cac756e on main. Nothing was deployed.

What was built

• src/Counter.sol holds a single shared count. Anyone can increment or decrement. Decrementing at zero reverts with a custom error instead of wrapping. Only the owner, fixed as an immutable at construction, can reset to zero. A zero-address owner is rejected at deployment.
• test/Counter.t.sol has 25 unit and fuzz tests. Every behaviour has a success case, and every failure mode has a revert test that also asserts state was left untouched. The increment overflow bound is exercised by writing storage directly.
• test/CounterInvariants.t.sol runs stateful fuzzing through a handler with a ghost model, checking the on-chain count always matches the model, never exceeds total increments, and the owner never changes.
• script/Counter.s.sol is a reviewable deploy script that reads the owner from an environment variable. It was never run and there are no broadcast artifacts.
• README.md documents behaviour, test coverage, assumptions, the one deployment parameter, and operational responsibilities, including that ownership can never be transferred.
• lib/forge-std/ is the upstream v1.16.1 release vendored as 35 plain files. There is no submodule and no .gitmodules.

Verification results

Check	Result
forge build	clean, no warnings, solc 0.8.30
forge test	28 passed, 0 failed
forge fmt --check	passes
Fresh git clone of the commit, same three commands	all pass
Mutation checks (drop zero guard, drop owner guard, increment by two, reset does nothing)	each mutant killed by 6 to 18 tests

Offline readiness relies on solc 0.8.30 being in the local compiler cache and on offline = true in foundry.toml, so forge never attempts a download. If the verifier runs on a machine whose cache lacks 0.8.30, the build will fail with a clear message rather than silently fetching, since no compiler binary can be committed.

Assumptions worth flagging

• The counter is global, not per-account, so any address can move it.
• Ownership is immutable. A lost or compromised owner key means reset is permanently gone or permanently exposed, and the only remedy is a new deployment. The README recommends a multisig.
• Tests are not an audit. The README says so explicitly.