Prototype paused admin participant AI support

Enable an existing AI difficulty for a human seat through admin controls without granting private access or advancing paused play. Preserve custody, credentials, takeback and separate paced resume. Bind atomic writes and outgoing-grant revocation to live authority, room/pause versions and active seat access with durable exact receipts.

Validation: types/lint, 5408 offline tests, build and 52 HTTP tests passed on source fingerprint 2157de0f4bb0b74d9760d52102601c52344cf674dee8ccd1d559f0a246a1d4ff; 22 authenticated admin HTTP groups, independent SQL/privacy/UI review, desktop/mobile and refresh checks. All 2098 baseline rooms and 4455 seats preserved. Migration 0015 is additive. Positive production admin QA awaits authorized access; full admin/rules scope remains unfinished.

docs/ADMIN_PANEL.md

@@ -13,7 +13,7 @@ recovery and persistence systems where suitable.
 | 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 | Remove disruptive participants or revoke access, manage appropriate restrictions, assist saved-seat recovery and host reassignment, and use supported AI takeover/replacement without losing forces, cards or decisions. | Missing |
+| 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. Participant restrictions/removal, access revocation, assisted recovery and further replacement remain. Existing lobby controls can reassign the host. | Prototyped, partial |
 | Saved-game operations | Create/list/download backups, validate imports, restore a selected checkpoint safely, and diagnose or resume interrupted automatic work through authoritative game actions. | Missing |
 | Operations and audit | Show server/build/storage health, room/player counts and actionable errors; provide maintenance controls and a searchable record of administrator actions. | Missing |
 
@@ -53,6 +53,10 @@ Disabling an account invalidates its sessions; later re-enabling it cannot resto
 them. The database refuses to disable, demote or delete the final enabled owner.
 No default key, public account creation or host-to-administrator promotion exists.
 
+[Participant AI](ADMIN_PARTICIPANT_AI.md) lets owners/operators support an absent
+human in a paused, started game. The player retains access and takeback controls;
+the administrator receives no private seat. Resume remains a separate action.
+
 The directory uses an explicit field allowlist, independent of any player view.
 It never returns hands, Traitors, predictions, plans, private messages, recovery
 records or raw saved state. Searches inspect only codes and public player names.
@@ -124,6 +128,8 @@ saved seats and revoked credentials. Private reports retain
 room IDs and safe outcomes, never keys/cookies. The container verifier provisions
 its own disposable QA account and checks admin-session continuity across restart
 and replacement, followed by the HTTP flow and HTTPS-proxy cookie behavior.
+Participant checks use another new QA room for paused AI enable, private-seat
+continuity, takeback and durable retries after resuming.
 
 Local browser checks cover sign-in, directory filters, refresh restoration and
 mobile layout. Final source-bound checks and separately recorded deployed