refactor(poll): implement core participation contract

tests/test_participation_contract.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+import unittest
+
+from govoplan_core.core.poll_participation import (
+    CAPABILITY_POLL_PARTICIPATION_GATEWAY as CORE_CAPABILITY,
+    PollGovernedInvitationCommand as CorePollGovernedInvitationCommand,
+    PollParticipationGatewayProvider as CorePollParticipationGatewayProvider,
+    PollParticipationPolicy as CorePollParticipationPolicy,
+)
+from govoplan_poll.backend.capabilities import SqlPollSchedulingProvider
+from govoplan_poll.backend.participation import (
+    CAPABILITY_POLL_PARTICIPATION_GATEWAY,
+    PollGovernedInvitationCommand,
+    PollParticipationGatewayProvider,
+    PollParticipationPolicy,
+)
+
+
+class PollParticipationCompatibilityTests(unittest.TestCase):
+    def test_legacy_imports_are_exact_core_contract_re_exports(self) -> None:
+        self.assertIs(CORE_CAPABILITY, CAPABILITY_POLL_PARTICIPATION_GATEWAY)
+        self.assertIs(CorePollGovernedInvitationCommand, PollGovernedInvitationCommand)
+        self.assertIs(CorePollParticipationPolicy, PollParticipationPolicy)
+        self.assertIs(CorePollParticipationGatewayProvider, PollParticipationGatewayProvider)
+
+    def test_sql_provider_implements_the_core_contract(self) -> None:
+        self.assertIsInstance(SqlPollSchedulingProvider(), CorePollParticipationGatewayProvider)
+
+
+if __name__ == "__main__":
+    unittest.main()