Finishes what 88221b0 started: sicurezza.md, audit-log.md and storico-bug.md
now describe the target behaviour too, the operator guides are corrected
against today's code, and api.md gains the missing /health/ready and
/admin/electrum sections plus every new error code in its catalog.
Harmonised names and owners across documents (the `resurrected_tx` pause
reason, the reconciler as the one that watches failed rows, the full
`winner_drawn` payload, a reason for an unanswered pre-payout pool check,
one corroboration-failure row per hash instead of one per tick).
Adds B-98 (coin selection stops at the first covering UTXO and refuses a
payable bet), tightens RND-40 to check both 1 and 400 participants and to
guard PUT /admin/config, and gives a stalled `closing` round a signal
(TX-29, closing_stalled).
Records three decisions confirmed on 2026-09-29: the draw's server_seed is
stored Fernet-encrypted until revealed (SEC-56, DAT-64), the chosen abuse
and key-check thresholds (SEC-49, SEC-54, SEC-55), and a broadcast
rejection is verified against every server before any coin is released,
so matching "already known" text is a shortcut, not a safety condition
(TX-04).
Spec only; no code changed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>