Stand up the Engine/PIP surface for MAT-WP-0001

Declare layer.yaml, add a Python engine over a local SQLite store,
and cover deterministic assessment, the §13 gap register, stance-map
inventory, claim guardrails, and the gate-house review path with tests.

Assistant: grok
Assistant-Session: 01a04ceb-150e-7e80-a542-ec8b1372e164

tests/test_claims_and_guardrail.py

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+from __future__ import annotations
+
+import pytest
+
+from maturity_engine.claims import compile_into_registry, gate_on_level
+from maturity_engine.engine import Engine
+from maturity_engine.errors import GuardrailError
+from conftest import INSTANT, evidence
+
+
+def test_claim_shape(engine):
+    assessment = engine.assess("estate", "asm", at=INSTANT)
+    claim = engine.claim(assessment)
+    body = claim.as_dict()
+    assert body["kind"] == "maturity-level"
+    assert body["issuer"] == "maturity-engine"
+    assert body["subject"] == "estate"
+    assert body["level_id"] == "ASM-0"
+    assert body["digest"]
+    assert "freshness_rule" in body
+
+
+def test_registry_compile_is_rejected(engine):
+    claim = engine.claim(engine.assess("estate", "asm", at=INSTANT))
+    with pytest.raises(GuardrailError, match="MUST NOT be compiled into registry"):
+        compile_into_registry(claim)
+
+
+def test_consumer_branch_is_rejected(engine):
+    claim = engine.claim(engine.assess("estate", "asm", at=INSTANT))
+    with pytest.raises(GuardrailError, match="MUST NOT gate a decision directly"):
+        gate_on_level(claim, minimum=3)
+
+
+def test_no_decision_surface():
+    assert not hasattr(Engine, "authorize")
+    assert not hasattr(Engine, "decide")
+    assert not hasattr(Engine, "may")
+    assert not hasattr(Engine, "allow")
+
+
+def test_assessment_emission_is_local_and_load_bearing(engine):
+    engine.assess("estate", "asm", at=INSTANT)
+    events = [item for item in engine.pending_events() if item["event_type"] == "assessment.recorded"]
+    assert len(events) == 1
+    payload = events[0]["payload"]
+    assert payload["class"] == "load-bearing"
+    assert "not altered or truncated after arrival" in payload["bound"]
+    assert "never sent" in payload["bound"]
+
+
+def test_outbox_failure_rolls_back_assessment(engine):
+    engine.store.fail_outbox = True
+    with pytest.raises(RuntimeError, match="outbox"):
+        engine.assess("estate", "pep-stance-publication", at=INSTANT)
+    assert engine.history("estate", "pep-stance-publication") == ()
+
+
+def test_heartbeat_is_a_positive_claim(engine):
+    engine.heartbeat(at=INSTANT)
+    beats = [item for item in engine.pending_events() if item["event_type"] == "maturity-engine.heartbeat"]
+    assert beats
+    assert beats[0]["payload"]["form"] == "heartbeat"
+
+
+def test_two_ladders_from_different_owners_can_be_claimed(engine):
+    for kind in ("stance-map-published", "stance-map-equality-test"):
+        engine.submit_evidence(evidence(engine, "ops-warden", kind))
+    asm = engine.claim(engine.assess("ops-warden", "asm", at=INSTANT))
+    psp = engine.claim(engine.assess("ops-warden", "pep-stance-publication", at=INSTANT))
+    assert asm.model_id != psp.model_id
+    assert psp.level_id == "PSP-2"