Govern distribution delivery channels

src/govoplan_policy/backend/policy_overrides.py

@@ -10,7 +10,7 @@ from govoplan_policy.backend.db.models import PolicyOverride
 
 
 POLICY_SCOPE_TYPES = frozenset({"system", "tenant", "group", "user"})
-POLICY_FAMILIES = frozenset({"definition", "view"})
+POLICY_FAMILIES = frozenset({"definition", "distribution_channels", "view"})
 
 
 class PolicyOverrideError(ValueError):
@@ -21,7 +21,9 @@ def normalize_policy_target(policy_family: str, target_key: str) -> tuple[str, s
     family = policy_family.strip().casefold()
     target = target_key.strip().casefold()
     if family not in POLICY_FAMILIES:
-        raise PolicyOverrideError("Policy family must be definition or view")
+        raise PolicyOverrideError(
+            "Policy family must be definition, distribution_channels, or view"
+        )
     if not target or len(target) > 120:
         raise PolicyOverrideError("Policy target must contain 1 to 120 characters")
     if family == "view" and target != "*":