Implemented the hook, vendored dependencies, real PoolManager integration tests, and README.

Offline checks passed:

• forge build --offline
• forge test --offline: 10 tests passed
• forge fmt --check

“Swapper” is explicitly transaction-origin analytics, never authorization. Static fees are supported; this design needs no dynamic-fee validation.

I found two low-severity issues and nothing high or medium. The hook does what the task asks and its tests check the right things. The findings are in .imd-findings.json, most severe first. I didn't change any repository file.

What I checked

• Build and tests: forge test --offline passes 10/10, including the fuzz test.
• Protected checks: I ran the protected suite against the hook's real creation code in a throwaway copy, with the address-flags value set to 0x40 (after-swap only). After I stubbed two missing helper files (see finding 2), all 3 hook checks pass: the permissions match the address, the code has no escape hatch, and outside callers are refused. The token suite skips, which is correct because there is no token.
• Contract review (src/SwapMilestoneHook.sol):
  • Only the after-swap permission is enabled, and it only accepts calls from the PoolManager.
  • It returns a zero delta, changes no fees, makes no external calls, and has no owner or admin.
  • It ignores sender and hookData.
  • Counts are kept separately per pool.
  • The Milestone event fires at every multiple of 100.
  • Counters stop at the maximum value instead of reverting.
  • Liquidity removal isn't hooked, so LPs can always exit.
• Dynamic fee: not requiring one is correct. The task only asks for that check "where the design needs a dynamic fee", and this design doesn't.

Findings

1. Low: "swapper" is recorded as tx.origin (line 53). I confirmed this with a proof of concept. Alice and Bob each pay for a swap, but a relayer sends both transactions. Their counts are 0 and the relayer's is 2. The same happens to smart-contract wallets (ERC-4337 accounts) and Safe multisig users. The README says this choice is deliberate and analytics-only, and no money depends on the count, so I didn't mark it blocking. Still, it doesn't match "per swapper" for those users, and no test covers a swap where the caller and the transaction sender differ.
2. Low, conditional: two files the protected suite imports don't exist. Hook.protected.t.sol imports src/HookFlags.sol and test/mocks/MockERC20.sol. If the verifier puts the suite under test/protected/univ4_hook/ and doesn't bring those files itself, the build fails with "Source not found". That placement is my guess from the import paths. If the verifier supplies the files, this finding doesn't apply.

My proof-of-concept test and the stubs existed only in the throwaway copy, which I've deleted.