feat(policy): add scheduling participant privacy contract

tests/test_scheduling_privacy_contract.py

@@ -0,0 +1,95 @@
+from __future__ import annotations
+
+import unittest
+
+from govoplan_core.core.modules import ModuleContext, ModuleManifest
+from govoplan_core.core.policy import (
+    CAPABILITY_POLICY_SCHEDULING_PARTICIPANT_PRIVACY,
+    PolicySourceStep,
+    SchedulingParticipantPrivacyDecision,
+    SchedulingParticipantPrivacyPolicy,
+    SchedulingParticipantPrivacyRequest,
+    scheduling_participant_privacy_policy,
+)
+from govoplan_core.core.registry import PlatformRegistry
+
+
+class _PrivacyPolicy:
+    def resolve_scheduling_participant_visibility(
+        self,
+        session: object,
+        *,
+        request: SchedulingParticipantPrivacyRequest,
+    ) -> SchedulingParticipantPrivacyDecision:
+        del session
+        return SchedulingParticipantPrivacyDecision(
+            effective_visibility="aggregates_only",
+            reason=f"Participant roster is restricted for {request.scheduling_request_id}.",
+            details={"requested_visibility": request.requested_visibility},
+        )
+
+
+class SchedulingPrivacyContractTests(unittest.TestCase):
+    def test_capability_name_and_request_context_are_stable(self) -> None:
+        self.assertEqual(
+            CAPABILITY_POLICY_SCHEDULING_PARTICIPANT_PRIVACY,
+            "policy.schedulingParticipantPrivacy",
+        )
+        request = SchedulingParticipantPrivacyRequest(
+            tenant_id="tenant-1",
+            scheduling_request_id="request-1",
+            participant_id="participant-1",
+            actor_user_id="user-1",
+            requested_visibility="names_and_statuses",
+            context={"request_status": "open"},
+        )
+
+        self.assertEqual(request.requested_visibility, "names_and_statuses")
+        self.assertEqual(request.context["request_status"], "open")
+
+    def test_decision_serializes_policy_provenance(self) -> None:
+        decision = SchedulingParticipantPrivacyDecision(
+            effective_visibility="aggregates_only",
+            reason="Tenant privacy policy restricts the participant roster.",
+            source_path=(
+                PolicySourceStep(
+                    scope_type="tenant",
+                    scope_id="tenant-1",
+                    label="Tenant",
+                    applied_fields=("scheduling_participant_visibility",),
+                ),
+            ),
+            details={"requested_visibility": "names_and_statuses"},
+        )
+
+        payload = decision.to_dict()
+        self.assertEqual(payload["effective_visibility"], "aggregates_only")
+        self.assertEqual(payload["source_path"][0]["path"], "tenant:tenant-1")
+        self.assertEqual(payload["details"]["requested_visibility"], "names_and_statuses")
+
+    def test_optional_provider_resolves_through_platform_registry(self) -> None:
+        provider = _PrivacyPolicy()
+        self.assertIsInstance(provider, SchedulingParticipantPrivacyPolicy)
+
+        registry = PlatformRegistry()
+        registry.register(
+            ModuleManifest(
+                id="policy_test",
+                name="Policy test",
+                version="test",
+                capability_factories={
+                    CAPABILITY_POLICY_SCHEDULING_PARTICIPANT_PRIVACY: lambda context: provider,
+                },
+            ),
+        )
+        registry.configure_capability_context(ModuleContext(registry=registry, settings=object()))
+
+        self.assertIs(scheduling_participant_privacy_policy(registry), provider)
+
+    def test_optional_provider_lookup_does_not_choose_a_fallback(self) -> None:
+        self.assertIsNone(scheduling_participant_privacy_policy(None))
+        self.assertIsNone(scheduling_participant_privacy_policy(PlatformRegistry()))
+
+
+if __name__ == "__main__":
+    unittest.main()