docs: mark FU-9 done + log FU-12 completed in follow-up backlog

FU-9 (playtest checklist) and FU-12 (velvet-auction group tools) both
shipped in the prior commit; update the backlog so it reflects reality.

Co-Authored-By: Claude <noreply@anthropic.com>

_bmad-output/prds/prd-mardonar-encounter-engine-2026-06-20/follow-up-stories.md

@@ -23,6 +23,12 @@ deferred, accepted as ship-and-break trade-offs, or left open. The feature set
 
 ---
 
+## Completed (2026-06-22)
+- **FU-12** *(added and closed same day)* — `velvet-auction` now exercises the group tools: `minPlayers: 3`, a `passiveReveals` entry (Insight/15), and a group Stealth check (`skill_check_group_emit`, `successRule: majority`); `character_status` added to its tool set. The `specsToolsConsistency` `NOT_YET_REFERENCED` allowlist is now empty (all 8 registered tools referenced by specs). See `specs/velvet-auction.yaml`.
+- **FU-9** — the 7-step manual pre-release multi-player playtest checklist is checked into the repo as a release gate at `docs/release-playtest-checklist.md` (previously buried only in the arch doc). The optional second-token live E2E remains open if the one-token constraint ever relaxes.
+
+---
+
 ## FU-1 — Durable timed-check timers + multi-instance locking
 - **status:** deferred · **confidence: high**
 - **Source:** PRD §3 Non-Goals ("Durable timers… Redis-TTL-backed timers are deferred (NFR-2)"); FR-5 (restart cancels pending timed check as fail); arch line 561 "Areas for Future Enhancement: durable timers / multi-instance locking (if scale lands)"; ADR-006 (in-process mutex with documented Lua swap path).
@@ -93,7 +99,7 @@ deferred, accepted as ship-and-break trade-offs, or left open. The feature set
   - If hidden: scoreboard shows only pass/fail (or the d20 total), not the modifier breakdown.
 
 ## FU-9 — Group-check live E2E gap (release-gate the manual playtest)
-- **status:** accepted risk → formalize · **confidence: high**
+- **status:** **done (2026-06-22)** — checklist checked in; optional second-token live E2E still open · **confidence: high**
 - **Source:** arch line 111 ("Group checks = unit + integration coverage only; no live E2E tier… one-token constraint… mitigated by… manual pre-release multi-player playtest checklist item in the release gate"); decision-log round 3 (Murat locks group-check testing = unit+integration-only w/ documented live-E2E gap).
 - **Today:** Group checks have unit + integration coverage only. Simultaneous multi-player fan-out, successRule N>1, per-user ephemeral delivery, and second-claimant rejection are **not** live-E2E covered. A manual pre-release multi-player playtest checklist is the safety net.
 - **Acceptance:**
@@ -124,7 +130,7 @@ deferred, accepted as ship-and-break trade-offs, or left open. The feature set
 ## Suggested prioritization
 1. **FU-2** (ConditionsReader) — unblocks full FR-31/FR-43 fidelity; relay-dependent, so longest lead time → start the contract-first schema now.
 2. **FU-8** (OQ-8) — a one-decision story; cheap to close and it affects every group-check scoreboard.
-3. **FU-9** (live E2E gap) — test debt that protects the most residual risk; cheap to formalize the checklist.
+3. ~~**FU-9** (live E2E gap)~~ — **done 2026-06-22** (`docs/release-playtest-checklist.md`).
 4. **FU-10 / FU-11** (verify items) — quick confirmations; convert to stories only if missing.
 5. **FU-1, FU-3, FU-4, FU-5, FU-6** — scope/trigger-gated; pull when the trigger lands (scale, campaign play, scenes, DM demand).
 6. **FU-7** — only if DM workflow demands it.