Record administrator failed attempts without storing credentials

Rejected administrator authentication and authorization attempts are now
recorded durably in a new additive admin_attempts table with a fixed reason
(invalid_key_format, unknown_or_disabled_key, missing_session,
unknown_or_expired_session, role_denied), the attempt kind, the attempted role
and an already-known account id. No key, key hash, session token, session hash,
request body, origin, address or user agent is stored, and the
unknown/disabled distinction is deliberately collapsed so the lookup cannot
become an account-enumeration oracle.

GET /api/admin/operations?attempts=1 returns seven-day per-reason counters plus
the twenty most recent attempts, newest first, to a live owner only, with
no-store and the same query guard as the other reads. The operations page adds
"List failed attempts" with the counters and the bounded sample, truncating each
account id to eight characters. Recording is best-effort inside the rejection
path, so a rejected request keeps its own answer even when the table is
unavailable, and the history never locks out, disables or revokes anything by
itself.

Evidence: tests/admin-attempts.test.ts asserts every recorded reason, the
kind/role/account fields, that successful sign-ins and privileged reads record
nothing, that no credential text appears anywhere in the page, the reporting
window, the twenty-row bound and the owner-only recheck after demotion, and that
a dropped attempts table leaves the original rejection answer unchanged. The
anonymous HTTP boundary denies ?attempts=1, and the panel was verified in the
real browser against a genuine recorded rejection. The shared AdminError moved
to db/admin-error.ts so the recorder and the access module no longer form a
value-import cycle. Offline suite 7,801/7,801 with typecheck and lint clean. No
game, seat, saved state or deployment changes.

docs/ADMIN_PANEL.md

@@ -9,13 +9,13 @@ recovery and persistence systems where suitable.
 
 | Area | Required behavior | Stage |
 | --- | --- | --- |
-| Administrator access | Personal access keys, server-enforced owner/operator/viewer roles, persistent eight-hour sessions and individual/all-session sign-out. [Owner-only account management](ADMIN_ACCOUNTS.md) adds a paginated directory, browser-created one-time keys, role changes, disabling and fresh-key rotation/re-enable with session revocation, live authority and exact retries. A room host is not a site administrator. Failed-attempt history and further operational permissions remain. | Prototyped, partial |
+| Administrator access | Personal access keys, server-enforced owner/operator/viewer roles, persistent eight-hour sessions and individual/all-session sign-out. [Owner-only account management](ADMIN_ACCOUNTS.md) adds a paginated directory, browser-created one-time keys, role changes, disabling and fresh-key rotation/re-enable with session revocation, live authority and exact retries. A room host is not a site administrator. [Failed-attempt history](ADMIN_ATTEMPTS.md) records rejected sign-ins and role denials without storing any credential; further operational permissions remain. | Prototyped, partial |
 | Room directory | Search room codes/public player names, filter status/rules/availability, sort and paginate; show host, roster, modules, game change time, pause/join flags and bounded decision ownership. Detailed setup/shared-window ownership remains. | Prototyped |
 | Create and configure | [Create a lobby](ADMIN_ROOM_CREATION.md) with an explicitly owned new host seat, Basic/Advanced preview and initial AI configuration; invite humans and use ordinary lobby controls/voluntary host-seat handover. [Neutral lobby configuration](ADMIN_LOBBY_CONFIGURATION.md) adds rules/modules, AI seats and host assignment to an existing human without private access. Reserved human seats remain. | Prototyped, partial |
 | Lifecycle and removal | [Pause/resume and joining locks](ADMIN_ROOM_CONTROLS.md), [administrative close/reopen](ADMIN_ROOM_CLOSURE.md) and [recoverable removal/restoration](ADMIN_ROOM_REMOVAL.md) have controls, durable audit, exact retries and player/AI enforcement. [Archive/unarchive](ADMIN_ROOM_ARCHIVE.md) has separate directory filters and exact retries. Permanent deletion and bulk actions remain missing. | Prototyped, partial |
 | Participant support | [Participant AI](ADMIN_PARTICIPANT_AI.md) enables an existing difficulty on an eligible human seat in a paused game, retaining access/takeback and private custody. [Discussion controls](ADMIN_DISCUSSION.md) mute/unmute new sends while retaining history and gameplay. Participant removal, access revocation, assisted recovery and further replacement remain. Existing lobby controls can reassign the host. | Prototyped, partial |
 | Saved-game operations | [Owner-only room backups](ADMIN_BACKUPS.md) capture/list/download a size-limited, version-fenced room snapshot without changing play or access; import validation, safe checkpoint restore and interrupted-work diagnosis/resume remain missing. | Prototyped, partial |
-| Operations and audit | [Action history](ADMIN_ACTION_HISTORY.md) searches existing durable operations with safe settings and role-limited reasons. The owner-only [operations page](../app/admin/operations/page.tsx) samples build revision, room/seat flags, JSON syntax failures and backup/export counts without exposing game contents. [Stalled-decision diagnosis](ADMIN_STALLED_DECISIONS.md) adds a bounded, read-only sample of live rooms whose public pending interaction has been idle longest, with aggregate counters. An explicit owner action runs read-only SQLite quick/foreign-key checks and returns only pass/fail, never corrupt row details. Failed-attempt records, disk capacity and maintenance controls remain. | Prototyped, partial |
+| Operations and audit | [Action history](ADMIN_ACTION_HISTORY.md) searches existing durable operations with safe settings and role-limited reasons. The owner-only [operations page](../app/admin/operations/page.tsx) samples build revision, room/seat flags, JSON syntax failures and backup/export counts without exposing game contents. [Stalled-decision diagnosis](ADMIN_STALLED_DECISIONS.md) adds a bounded, read-only sample of live rooms whose public pending interaction has been idle longest, with aggregate counters. An explicit owner action runs read-only SQLite quick/foreign-key checks and returns only pass/fail, never corrupt row details. [Failed-attempt history](ADMIN_ATTEMPTS.md) records rejected authentication and authorization attempts with a fixed reason, the attempted role and an already-known account id — never a key, token, body or address — and exposes seven-day counters plus a bounded recent sample to the owner. Disk capacity and maintenance controls remain. | Prototyped, partial |
 
 Track each area through Missing, Prototyped, Integrated, Verified and Polished.
 As implementation begins, link its controls, server actions, persistence,
@@ -84,6 +84,14 @@ The check can take time; a failed check calls for a protected snapshot and
 private diagnosis, not automatic repair. It does not prove disk capacity,
 backup recoverability or valid game rules.
 
+[Failed-attempt history](ADMIN_ATTEMPTS.md) adds **List failed attempts**: seven-day
+per-reason counters and the twenty most recent rejected administrator requests —
+malformed, unknown or disabled keys, missing, unknown, expired or revoked
+sessions, and role-denied actions. Recording is best-effort inside the rejection
+path and stores no credential; the read repeats live owner authority and
+answers `no-store`. The history is diagnostic: it never locks out, disables or
+revokes anything by itself.
+
 [Stalled-decision diagnosis](ADMIN_STALLED_DECISIONS.md) adds **List stalled
 decisions**: a bounded, read-only sample of at most ten live rooms whose public
 pending interaction — a decision, response, Truthtrance or phase opening — has