Build Keel v2 contracts (part 1 of 2): a memecoin launchpad on Uniswap v4. Foundry, Solidity 0.8.26, tests on a mainnet fork. Code only: no deployment, no broadcast.

CONTRACTS

1. KeelV2Token: ERC20 clone, 1e9 supply, 18 decimals, minted once to the factory. No owner, no mint, no transfer limits. Balance checkpoints: balanceAt(account, blockNumber) returns the balance at the end of that block; written on every balance change incl. transfers to/from the PoolManager.
2. KeelV2Hook: one shared hook for all pools. Not upgradeable. Holds all fee money. Request the full permission set future modules may need: afterInitialize, beforeAddLiquidity, beforeSwap, afterSwap, beforeSwapReturnDelta, afterSwapReturnDelta.
3. KeelV2Factory: launch(name, symbol, metadata, quote, startTick, baseFeeBps). Clones token, creates pool token/quote (LP fee 0, this hook), adds the whole supply single-sided from startTick up, liquidity locked forever. Caller becomes creator.
4. FixedRateModule: first rules module (below).
5. script/Deploy.s.sol: deploys all, mines the hook CREATE2 salt, takes an explicit owner address. Dry run only.

RULES MODULES

• Interface: feeBps(poolId, isBuy, context) view returns uint16. Modules hold no money and cannot move funds.
• At launch the pool stores the current module address; it is immutable and the owner has no function to change it. Owner may register a new module only for future launches.
• FixedRateModule: returns the creator's base rate (100 to 500 bps). Creator may lower it any time; a raise is at most +100 bps, scheduled, applied after 24 h, cancellable.

FEES (hook)

• Fee always taken in the quote currency: from input on buys, from output on sells. Never sell the meme token for fees. Only exact-input swaps are supported; exact-output swaps must revert.
• Split of the base fee: 80% creator, 20% team, fixed in code. Round the total fee up; creator gets 80% of it rounded down, team gets the rest. Math must be correct for 6, 8 and 18 decimal quotes.
• Launch schedule: scheduled rate starts at 9900 bps and falls linearly to the base rate over decaySeconds (30 to 600, default 120). Effective rate = max(scheduled rate, current base rate). A base rate change during the schedule does not restart it. The part above base goes 100% to team. No wallet is exempt.
• Fees accrue per pool; claimCreator(token, to) and claimTeam(quote, to), where to may be any address incl. contracts. Funds leave the hook only via these claims and swap settlement.
• Only the factory adds liquidity; nobody removes it.

CREATOR ROLE

• transferCreator by creator. lastActive updates on any creator action and ping().
• setCreatorByTakeover(token, newCreator): callable only by a takeover contract the owner may set once (unset in this part), and only if lastActive is older than 30 days. The hook itself enforces this check; the takeover contract cannot bypass it. Already accrued fees stay with the old creator.

OWNER (multisig)

• Pause new launches, allowlist quote bases (ETH plus ERC20s; reject fee-on-transfer and rebasing; support 6, 8, 18 decimals), startTick bounds per base, decaySeconds and module for new launches, team recipient, set takeover contract once. Two-step ownership.
• Owner can never change an existing pool's module, rate, split, creator, liquidity or accrued fees.

INVARIANTS

• For each quote: hook balance >= all unclaimed fees.
• No selfdestruct, no delegatecall, reentrancy-safe claims.

TESTS

Launch with ETH and with a 6-decimal base; locked liquidity; outside liquidity add reverts; fee on buys and sells; 80/20 split and rounding; launch schedule at several timestamps; creator lowers the rate during the schedule; module fixed per pool after a new module is registered; rate lower and raise rules; takeover hook rejects early and unknown callers; exact-output revert; pause and owner limits; claims; fuzz the balance invariant.

Deliver: src, test, script, README listing every parameter, event, owner power and known limits.

Token name: kkkkk

Token symbol: lllll