feat: implement prepared account claims

src/user_engine/ports.py

@@ -26,6 +26,7 @@ from user_engine.domain import (
     IdentityFactor,
     Membership,
     OutboxEvent,
+    PreparedAccount,
     ProfileValue,
     RegistrationSession,
     TenantAccount,
@@ -148,6 +149,17 @@ class UserEngineStore(Protocol):
     def factors_for_user(self, user_id: str) -> tuple[IdentityFactor, ...]:
         """Return verified factors attached to a user."""
 
+    def save_prepared_account(self, account: PreparedAccount) -> None:
+        """Create or replace a prepared account package."""
+
+    def prepared_account(self, prepared_account_id: str) -> PreparedAccount | None:
+        """Return a prepared account package by id."""
+
+    def prepared_accounts_for_tenant(
+        self, tenant: str
+    ) -> tuple[PreparedAccount, ...]:
+        """Return prepared account packages for a tenant."""
+
     def save_profile_value(self, value: ProfileValue) -> None:
         """Create or replace a profile value."""