feat: define campaign archive encryption policy contract

src/govoplan_core/core/policy.py

@@ -7,6 +7,14 @@ from urllib.parse import quote, unquote
 from govoplan_core.core.access import PrincipalRef
 
 PolicyScopeType = Literal["system", "tenant", "user", "group", "campaign"]
+CampaignArchiveEncryptionMethod = Literal["aes", "zip_standard"]
+CampaignArchivePasswordDeliveryChannel = Literal[
+    "separate_mail",
+    "sms",
+    "letter",
+    "phone",
+    "in_person",
+]
 SchedulingParticipantVisibility = Literal["aggregates_only", "names_and_statuses"]
 DefinitionScopeType = Literal["system", "tenant", "group", "user"]
 DefinitionKind = Literal["flow", "template"]
@@ -45,6 +53,7 @@ CAPABILITY_POLICY_SCHEDULING_PARTICIPANT_PRIVACY = "policy.schedulingParticipant
 CAPABILITY_POLICY_DEFINITION_GOVERNANCE = "policy.definitionGovernance"
 CAPABILITY_POLICY_VIEW_GOVERNANCE = "policy.viewGovernance"
 CAPABILITY_POLICY_FUNCTION_ASSIGNMENT_GOVERNANCE = "policy.functionAssignmentGovernance"
+CAPABILITY_POLICY_CAMPAIGN_ARCHIVE_ENCRYPTION = "policy.campaignArchiveEncryption"
 
 POLICY_SCOPE_TYPES: tuple[PolicyScopeType, ...] = (
     "system",
@@ -182,6 +191,73 @@ class PolicyDecision:
         }
 
 
+@dataclass(frozen=True, slots=True)
+class CampaignArchiveEncryptionRequest:
+    """Context required to resolve one Campaign archive-encryption ceiling.
+
+    The owning module supplies the stable Campaign and owner references. Policy
+    owns hierarchy evaluation; Campaign owns archive configuration and evidence.
+    """
+
+    tenant_id: str
+    campaign_id: str
+    owner_type: Literal["user", "group"] | None = None
+    owner_id: str | None = None
+
+
+@dataclass(frozen=True, slots=True)
+class CampaignArchiveEncryptionDecision:
+    allowed_password_encryption_methods: frozenset[CampaignArchiveEncryptionMethod]
+    allowed_password_delivery_channels: frozenset[
+        CampaignArchivePasswordDeliveryChannel
+    ]
+    policy_hash: str
+    source_path: tuple[PolicySourceStep, ...] = ()
+    reason: str | None = None
+    diagnostics: tuple[Mapping[str, Any], ...] = ()
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "allowed_password_encryption_methods": sorted(
+                self.allowed_password_encryption_methods
+            ),
+            "allowed_password_delivery_channels": sorted(
+                self.allowed_password_delivery_channels
+            ),
+            "policy_hash": self.policy_hash,
+            "source_path": [step.to_dict() for step in self.source_path],
+            "reason": self.reason,
+            "diagnostics": [dict(item) for item in self.diagnostics],
+        }
+
+
+@runtime_checkable
+class CampaignArchiveEncryptionPolicy(Protocol):
+    def resolve_campaign_archive_encryption(
+        self,
+        session: object | None = None,
+        *,
+        request: CampaignArchiveEncryptionRequest,
+    ) -> CampaignArchiveEncryptionDecision: ...
+
+
+def campaign_archive_encryption_policy(
+    registry: object | None,
+) -> CampaignArchiveEncryptionPolicy | None:
+    if (
+        registry is None
+        or not hasattr(registry, "has_capability")
+        or not registry.has_capability(CAPABILITY_POLICY_CAMPAIGN_ARCHIVE_ENCRYPTION)
+    ):
+        return None
+    capability = registry.capability(CAPABILITY_POLICY_CAMPAIGN_ARCHIVE_ENCRYPTION)
+    return (
+        capability
+        if isinstance(capability, CampaignArchiveEncryptionPolicy)
+        else None
+    )
+
+
 @dataclass(frozen=True, slots=True)
 class FunctionAssignmentGovernanceRequest:
     tenant_id: str