feat(scheduling): enforce participant roster privacy

src/govoplan_scheduling/backend/manifest.py

@@ -19,6 +19,7 @@ from govoplan_core.core.modules import (
 )
 from govoplan_core.db.base import Base
 from govoplan_core.core.poll import CAPABILITY_POLL_SCHEDULING
+from govoplan_core.core.policy import CAPABILITY_POLICY_SCHEDULING_PARTICIPANT_PRIVACY
 from govoplan_scheduling.backend.db import models as scheduling_models  # noqa: F401 - populate Scheduling ORM metadata
 
 MODULE_ID = "scheduling"
@@ -129,11 +130,12 @@ manifest = ModuleManifest(
     name=MODULE_NAME,
     version=MODULE_VERSION,
     dependencies=("poll",),
-    optional_dependencies=("access", "calendar", "appointments", "evaluation", "mail", "notifications", "portal", "workflow", "tasks", "idm", "organizations", "addresses"),
+    optional_dependencies=("access", "calendar", "appointments", "evaluation", "mail", "notifications", "policy", "portal", "workflow", "tasks", "idm", "organizations", "addresses"),
     optional_capabilities=(
         CAPABILITY_AUTH_PRINCIPAL_RESOLVER,
         CAPABILITY_AUTH_PERMISSION_EVALUATOR,
         CAPABILITY_CALENDAR_SCHEDULING,
+        CAPABILITY_POLICY_SCHEDULING_PARTICIPANT_PRIVACY,
     ),
     required_capabilities=(CAPABILITY_POLL_SCHEDULING,),
     provides_interfaces=(