feat: finish ZONE-WP-0003 Engine/PIP freeze and claim mapping

Declare the layer in layer.yaml, check it against INTENT.md, and fail
make check on a new Tooling client or HTTP decision surface. Record the
six statute §10 artifacts for the 2026-08-23 cut, name access-engine on
the README, and offer a non-schema PIP field mapping to Taxonomy.

Assistant: grok
Assistant-Session: 01a04ceb-0745-7ae1-9e26-0d10e5d52b8b

layer.yaml

@@ -0,0 +1,65 @@
+# zone-engine — NetKingdom security layer declaration
+#
+# Framework: net-kingdom/canon/standards/security-layer-model_v0.7.md
+# Companion: net-kingdom/SECURITY-COMPANION.md v0.2
+# Declaration: INTENT.md (this repository's own voice, §11)
+# Validate:    python3 tools/check_layer_conformance.py
+#
+# §11 requires a machine-readable form because prose cannot distinguish a
+# declaration from a transcribed review. Shape adapted from kings-guard's
+# no-contact declaration, offered estate-wide under §11.
+#
+# Catalogued as Engine / PIP for zone identity and membership, offline
+# reference conformance per the 2026-08-23 disposition. There is no
+# Tooling contact, no PEP, and no authorization decision surface.
+
+schema_version: "0.1"
+framework: netkingdom-security-layer-model
+standard_version: "0.7"
+repository: zone-engine
+layer: engine
+role: pip
+declared_by: INTENT.md
+declared_at: "2026-08-29"
+
+# §4 catalog entry, transcribed so drift is visible. The standard is
+# authoritative for the row; this records what we understand ourselves
+# to have been assigned.
+catalog_entry:
+  owns:
+    - zone identity and membership
+  form: offline reference conformance (2026-08-23 disposition)
+  pep_shaped: false
+
+# §5 / §11: every direct contact with a Tooling-layer system (a §4 Tooling
+# row), one entry each. Empty is a claim. tools/check_layer_conformance.py
+# fails if a Tooling client or a decision surface appears under tools/.
+tooling_contacts: []
+
+# No pep_stance path. This repository causes no protected side effect.
+
+# §11 requires non-Tooling clients to be recorded so the check is total.
+# There is no library client in this repository. Work-record writes happen
+# through the State Hub CLI / agent sessions, not through tools/.
+non_tooling_clients:
+  - id: state-hub-work-records
+    target: state-hub
+    layer: not-catalogued
+    operation: "HTTP via statehub CLI / agent sessions for work records and progress events"
+    write: true
+    in_tree: false
+    note: >-
+      Outside §5 by the v0.5 scope rule: "Tooling-layer system" means a §4
+      Tooling row, and state-hub is not one. Recorded, not policed. Carries no
+      security authority and no secret payload. No import of a State Hub
+      client exists under tools/.
+
+# A live Engine API is not an unowned capability this repository currently
+# owes. The catalog records the offline form. Growing one would be a §10
+# layer change, not a gap to close in place.
+unowned_capabilities: []
+
+declared_shapes:
+  "5.1": []
+  "5.2": []
+  "5.3": []