feat: add status and payment capability contracts

tests/test_application_status_contract.py

@@ -0,0 +1,64 @@
+from datetime import UTC, datetime
+import unittest
+
+from govoplan_core.core.application_status import (
+    CAPABILITY_APPLICATION_STATUS_PROJECTION,
+    application_status_projection_provider,
+)
+
+
+class _Provider:
+    def tenant_id_for_tracking_id(self, session, *, tracking_id):
+        return "tenant-1"
+
+    def public_access_challenge(self, session, *, tracking_id):
+        return {"tracking_id": tracking_id, "mode": "permanent_link"}
+
+    def get_authenticated_projection(
+        self, session, principal, *, tracking_id, observed_at
+    ):
+        return {"tracking_id": tracking_id, "status": "submitted"}
+
+    def get_public_projection(self, session, *, tracking_id, token, observed_at):
+        return {"tracking_id": tracking_id, "status": "submitted"}
+
+    def request_email_link(self, session, *, tracking_id, email, requested_at):
+        return True
+
+
+class _Registry:
+    def __init__(self, provider):
+        self.provider = provider
+
+    def has_capability(self, name):
+        return name == CAPABILITY_APPLICATION_STATUS_PROJECTION
+
+    def capability(self, name):
+        return self.provider
+
+
+class ApplicationStatusContractTests(unittest.TestCase):
+    def test_resolves_only_structurally_complete_provider(self):
+        provider = _Provider()
+        resolved = application_status_projection_provider(_Registry(provider))
+
+        self.assertIs(provider, resolved)
+        self.assertEqual(
+            "tenant-1",
+            resolved.tenant_id_for_tracking_id(None, tracking_id="tracking-1"),
+        )
+        self.assertTrue(
+            resolved.request_email_link(
+                None,
+                tracking_id="tracking-1",
+                email="resident@example.test",
+                requested_at=datetime(2026, 8, 19, tzinfo=UTC),
+            )
+        )
+
+    def test_rejects_incomplete_provider(self):
+        self.assertIsNone(application_status_projection_provider(_Registry(object())))
+
+
+if __name__ == "__main__":
+    unittest.main()