Release Circle (ERC-20 symbol CIRC) on Sepolia as an evm_project: the fixed-supply launch token plus one application contract.

Token: Circle (CIRC), total supply 1,000,000,000 CIRC with 18 decimals, minted once to the deployer.

Application contract: SavingsCircle.

Currency: CIRC is the app's working currency. SavingsCircle takes the CIRC address as its only constructor argument (constructorArgs ["$token"]), stores it immutable, exposes it as token(), and holds no CIRC at deploy; members get CIRC by swapping Sepolia ETH in the launch pool the factory seeds. Every payment in is approve + SafeERC20.safeTransferFrom (permit not required).

SavingsCircle has no payable function and no receive/fallback, so it never holds ETH. Payouts are pull-based (the recipient calls to collect; nothing is pushed to third parties), follow checks-effects-interactions and are nonReentrant. No owner, admin, pause or upgrade path.

A rotating savings circle (ROSCA) in CIRC, many circles by id. create(contribution, roundLength, seats): contribution >= 1 CIRC, roundLength 1 hour to 30 days, seats 2 to 10; the creator takes seat 0. join(id) takes the next free seat (one seat per address) until full. Joining (including the creator's seat) pulls a bond of (seats - 1) x contribution, so defaulting after being paid never profits in any seat.

If a circle is not full within 7 days of creation, anyone may cancel it and every bond becomes withdrawable. When the last seat fills, round 0 starts at that block; round r runs [start + r * roundLength, start + (r + 1) * roundLength). contribute(id): once per member per round, only inside the current round, pulls exactly contribution. A member who does not contribute in some round is in default from then on: further contribute calls revert and they lose any later turn.

Seat r receives round r: after round r ends, anyone may call closeRound(id, r) (rounds close in order). If seat r contributed in every round 0..r, the round's pot (that round's contributions plus any carry) is credited to seat r; otherwise the pot carries into round r + 1.

After the last round closes: members never in default get their bond back; the final carry plus forfeited bonds are split equally among members never in default, or, if none, among members who contributed at least once (remainder wei to the lowest such seat); if nobody ever contributed, every bond is returned to its member. withdraw() pays credited CIRC.

Views: circle(id), circleCount(), member(id, seat), inDefault(id, account), currentRound(id), token().

Events: Created, Joined, Cancelled, Contributed(id, round, member), RoundClosed(id, round, recipient, pot, carried), Finalized.

Tests (Foundry) must cover: seat limits, the 7-day cancel, round windows at their exact edges, a missed round forfeiting a later turn and carrying the pot, closing rounds out of order, the final split with and without members in good standing, a circle where nobody contributes, and the invariant that CIRC held equals bonds held + open pots + carry + withdrawable balances.

The independent adversarial review must attack: an early recipient defaulting after being paid (show the (seats - 1) x contribution bond makes that unprofitable for every seat), double contribution or double payout in one round, closing a round early, and remainder or carry arithmetic at the final split.

Deploy through the project factory, then publish a one-page website to open a circle, join (approve the bond), contribute each round, and see seats, whose turn it is, who is in default and the pot.

The page reads the CIRC address from SavingsCircle.token(), shows the connected wallet's CIRC balance, allowance and withdrawable balance, has an Approve step before every paying action and a Withdraw button, and says that CIRC comes from swapping Sepolia ETH in the launch pool (no in-page swap). Lists come from contract views and events only (no backend, no indexer). Keep it to one small page; the static export has index.html in dist/.