feat(deploy): add engine node intelligence transition

infra/deploy-runner/README.md

@@ -253,6 +253,65 @@ become `custom` and remain exact; they are never elevated. The artifact does not
 touch UI, n8n, credentials, agent tokens, workflow graphs, databases or runtime
 payloads.
 
+## Engine L2 node-intelligence transition
+
+The node-intelligence transition is an additive Engine-owned deployment domain.
+It does not merge Ontology, provider APIs or Ops into the Engine MCP. It pins the
+reviewed upstream `n8n-mcp` implementation at package `2.33.2`, commit
+`974a9fb3492fe2c4984ee0549085d531cdc6242a`, and exposes only the safe NDC L2
+projection through the existing Engine Agent gateway. Upstream management and
+write tools are not forwarded.
+
+Production never clones, pulls, installs or builds this dependency. The builder
+saves the reviewed `linux/amd64` image once, embeds that exact archive in a
+data-only activation artifact and records both the archive and image-config
+digests. The runner validates every inner blob, revision label, entrypoint,
+command and platform before an offline `docker image load`; Compose then uses
+the fixed tag with `pull_policy: never` and `--pull never`.
+
+Build a fresh activation/rollback pair:
+
+```bash
+node infra/deploy-runner/build-engine-node-intelligence-artifacts.mjs \
+  YYYYMMDD-NNN
+```
+
+The activation exact set is:
+
+- `nodedc-source/server/nodeIntelligence`
+- `nodedc-source/server/routes/engineAgentGateway.js`
+- `nodedc-source/services/node-intelligence`
+
+The runtime adds only `nodedc-node-intelligence` and recreates the existing
+`nodedc-backend`; n8n, UI, databases, L1, provider services and volumes are not
+selected. The sidecar has no host port, runs as `11007:11007`, has a read-only
+root filesystem, drops all capabilities and receives no Engine or provider
+credential. Its independent MCP bearer is created by the root-owned runner as a
+read-only file and mounted only into the sidecar and backend. It never appears
+in an artifact, shared environment file, log or MCP response.
+
+Acceptance requires the exact image/container/mount/security inventory,
+immutable backend identity and live authenticated `get_node`, `validate_node`
+and `validate_workflow` calls. Any apply failure restores source and runtime
+automatically. The separate rollback artifact first removes only the sidecar
+without volumes, restores the pinned inactive gateway, and recreates only the
+verified backend. Loaded images and failed candidate source are retained for
+audit rather than destructively deleted.
+
+Stage the reviewed runner under a unique candidate name first:
+
+```text
+/volume1/docker/nodedc-deploy/runner-install/candidates/
+  nodedc-deploy.engine-node-intelligence-YYYYMMDD-NNN
+```
+
+Do not overwrite the canonical staging candidate while another deploy may be in
+flight. After the no-lock/no-process gate, promote the exact candidate in a
+standalone root step, run `verify-install`, then invoke a fresh process for
+activation `plan` and only then `apply`. The generated plan/apply runbook carries
+the runner, activation and rollback SHA-256 values and is staged beside the
+unique runner candidate.
+
 `module-foundry` is an independent, authenticated application component. Its
 artifact contains source and compose infrastructure only; its live
 `/volume1/docker/nodedc-platform/module-foundry/source/.env` is root-owned and