feat: add chat replay verification

packages/casan-platform/README.md

@@ -19,7 +19,7 @@ Optional layer for teams that want UI / dashboard / visibility. Packages: `casan
 | RBAC + approval inbox | ✅ local-prod done | Settings + kill-switch API RBAC enforcement, approval inbox/delegation/oversight, SoD, governed setting proposal apply, and local OIDC claim→role mapping smoke are done. Enterprise IdP rollout remains production follow-up. |
 | Evidence Pack Viewer | 📋 planned | reads `docs/output/casan/evidence-packs/` |
 | Attack Battery Viewer | 📋 planned | reads red-team corpus + H4 recall results |
-| Read-only Ask CASAN + Operator + agent selection + operator loop-hold | 🟡 MVP-0/1 done+test; MVP-2 Track 4 + OPERATOR Track 5/6 done | Plan-18: `POST /api/v1/chat/ask`, `GET /api/v1/chat/actions`, `GET /api/v1/chat/agents` + `/chat`, backed by harness `chat-turn.py`, `chat-agent-resolver.py`, and Plan-17 `loop-run.sh` |
+| Read-only Ask CASAN + Operator + agent selection + operator loop-hold + replay | 🟡 MVP-0/1 done+test; MVP-2 Track 4 + OPERATOR Track 5/6 + Track 8.1/8.2 done | Plan-18: `POST /api/v1/chat/ask`, `GET /api/v1/chat/actions`, `GET /api/v1/chat/agents`, `GET /api/v1/chat/replay` + `/chat`, backed by harness `chat-turn.py`, `chat-agent-resolver.py`, `chat-replay.py`, and Plan-17 `loop-run.sh` |
 | Gitea webhook integration | 📋 planned | trigger gate / publish evidence on push |
 
 ## Build (preview)
@@ -29,6 +29,6 @@ scripts/package-release.sh platform     # → dist/casan-platform-preview-vX.Y.Z
 The bundle includes a `PREVIEW-INCOMPLETE.txt` marker. Do not treat it as a finished product.
 
 ## To implement later
-Start from Plan-15 RAI view or Plan-18 MVP-2 Track 8 (replay/widget) or CODEGEN-as-loop. Keep new numbers
+Start from Plan-15 RAI view or Plan-18 MVP-2 Track 8.3/8.4 (replay widget / approvals escalation) or CODEGEN-as-loop. Keep new numbers
 evidence-backed with provenance; any write/governed action must continue to route through
 harness RBAC, approval, and audit primitives.