docs: containerization plan + PRD D15 (tiered deployment, standalone v1 bar)

docs/PRD.md

@@ -197,7 +197,24 @@ conflict must amend one of them explicitly, never fork a third document
 - A second writable task store beside PostgreSQL (native-kanban-sot invariants).
 - Fully-designed federation in v1 (D3 — roadmap placeholder only).
 
-### 12. Decision registry
+#
+### D15 — Tiered containerized deployment (2026-08-30, containerization lane)
+
+The stack ships a tiered deployment target, additive to the architecture
+gate (D8): (1) Standalone tier — docker compose is the canonical
+single-host deployment: postgres, valkey, openbao, gateway, appservice
+and the served webUI in one composition, with migrations, health checks,
+and a documented install/upgrade path; the registry (CI-published
+images) is the only deployment source. (2) Enterprise tier — Kubernetes
+manifests for the same service set, phase-gated on the standalone tier
+holding its acceptance bar. The v1 acceptance bar for the standalone
+tier: compose-up healthy; webUI hosts agent chat; an in-stack agent can
+open a PR to this repo; CI validates it; the running deployment adopts
+the merged change (pull + restart). Federation (D3 clause) remains
+deferred and unforeclosed. Implementation plan:
+docs/plans/2026-08-30_containerization.md.
+
+## 12. Decision registry
 
 | ID  | Decision (short form)                                                                                              |
 | --- | ------------------------------------------------------------------------------------------------------------------ |

docs/plans/2026-08-30_containerization.md

@@ -0,0 +1,77 @@
+# Plan — Stack Containerization (tiered deployment)
+
+Status: DRAFT for review. Charter: fleet/lanes/stack-containerization
+(brain) NORTH-STAR.md; PRD amendment in the same PR adds D15.
+Supersedes nothing; sequences the absorbed M4 remainder per its lane.
+
+## Measured baseline (origin/next @ 143ba0f5, 2026-08-30)
+
+- `docker-compose.yml`: dev infrastructure only — postgres (pgvector),
+  valkey, otel-collector, jaeger. No application services.
+- `docker-compose.federated.yml`: standalone overlay for the FEDERATED
+  storage tier (own postgres/valkey; port-conflicts the base stack by
+  design). Not an app deployment.
+- `docker/gateway.Dockerfile`, `docker/appservice.Dockerfile`:
+  multi-stage production builds (node:22-alpine) EXIST; the gateway image
+  includes the web SPA bundle (#1444).
+- CI (`publish.yml`) builds and publishes these images (next-channel
+  prereleases + main stable), and runs `verify:release` fail-closed.
+- Gap: no stack-level composition wires gateway+appservice+data plane
+  into one deployable unit; no blessed install/upgrade path; no
+  in-container agent-runtime story for the dogfood loop.
+
+## Target (PRD D15 amendment)
+
+Tiered deployment, additive to the existing architecture:
+
+1. **Standalone tier (v1 bar)**: `docker compose up` on one host brings
+   postgres, valkey, openbao, gateway, appservice (and the webUI the
+   gateway serves) to healthy; migrations apply; the webUI hosts agent
+   chat; an in-stack agent can read this repo and open a PR; CI
+   validates; the deployment adopts merged images (pull + restart).
+2. **Enterprise tier (post-v1)**: Kubernetes manifests (or Helm) for the
+   same service set, phase-gated on the standalone bar holding.
+
+## Phases
+
+### Phase A — blessed standalone compose
+- A1 Compose service definitions for gateway + appservice joining the
+  existing infra compose (profiles: `dev` keeps today's behavior;
+  `stack` adds the app tier), with health checks and dependency order.
+- A2 Migrations on boot (or an explicit migrate step) with idempotency
+  and version pinning; init-db.sql folded into pg-init.
+- A3 Openbao in the compose set (secret plumbing for the app tier).
+- A4 `.env.example` + `mosaic.config.json` defaults documented for the
+  standalone mode; mode recorded per the mode-conversion contract.
+- A5 Smoke: `docker compose --profile stack up` green on a scratch host;
+  webUI served; agent chat reachable; failures catalogued and fixed.
+- Acceptance: the five-point NORTH-STAR bar measured live.
+
+### Phase B — component completion
+- Decompose JIT from A5's catalogue. Known candidates: agent runtime
+  bits (brain/tool access paths in-container), repo credentials for the
+  dogfood agent, watch/comms surfaces inside the deployment.
+
+### Phase C — CI/CD parity
+- Publish pipeline is the only image source (already true); add the
+  deployment-side pull/upgrade path (compose pull + migrate + restart =
+  next iteration); document the promotion flow next -> registry ->
+  deployment.
+
+### Phase D — coordinator integration (GATED)
+- Blocked until the guides-proposed control-plane refactor lands; then
+  wire `mosaic coord` service lifecycle per that design.
+
+### Phase E — enterprise tier
+- k8s manifests/Helm for the same set; phase-gated on Phase A holding.
+
+### Absorbed M4 remainder
+- M4-3 pivot: KBN-101 foundation first (per ruling R6), then expand DDL.
+- M4-5: lands inside Phase B/C where natural.
+- M4-6 (composes M4-1+M4-4): last, as designed.
+
+## Non-goals (v1)
+
+- No Kubernetes in v1; no multi-host federation; no replacement of the
+  fleet's brain-based seats (the stack is an additional operator
+  surface); no on-host image builds for deployment (registry only).