All bets of all rounds paid one address (m/84'/746'/0'/1/0), so its history
grew forever, other rounds' money and stray coins mixed with a round's own, and
the payout picked from everything it held.
- hd.py: derive_pool_key/derive_pool_address(round_id) on branch 2
(m/84'/746'/0'/2/<round_id>); no argument is the reserve address 1/0.
derive_round_pool_key checks the key against the address stored on the round,
so a payout can never be signed for money its key does not control.
- rounds.pool_address (migration 477bddae1a84, existing rounds backfilled with
the reserve address since that is where their bets went; add_column, not a
batch alter, so the expression indexes stay): written in the transaction that
inserts the round, once its id exists.
- place_bet pays round.pool_address; the payout reads, signs and takes change at
the round's own address; own_address_for and bump_fee's _signing_context follow
the round (confirmation poller and reconciler pass round_id).
- Withdrawals to any round pool address, the reserve address or fee_address are
refused (withdrawal_to_platform_address, 400, all seven languages).
- GET /rounds/current and GET /admin/rounds expose pool_address.
- RND-22/DAT-11 stay "da implementare" for B-82: the payout still spends every
confirmed coin at the round's address, not only the participants' outpoints
(participants carry no bet_vout yet).
- tests/unit/conftest.py: every test now gets a throwaway master key. Opening a
round derives an address, and tests that merely opened a round were silently
reading the real key from the local .env.
- Existing tests changed because the spec changed: payout fixtures give their
round a pool_address; the reconciler's address-cache test uses two payouts of
one round (rows of different rounds no longer share an address);
own_address_for now takes the round id.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>