feat: add reusable workflow definition graphs

tests/test_manifest.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+import unittest
+
+from govoplan_workflow.backend.manifest import (
+    DEFINITION_READ_SCOPE,
+    DEFINITION_WRITE_SCOPE,
+    get_manifest,
+)
+
+
+class WorkflowManifestTests(unittest.TestCase):
+    def test_manifest_exposes_definition_contracts(self) -> None:
+        manifest = get_manifest()
+
+        self.assertEqual(manifest.id, "workflow")
+        self.assertIn(
+            "workflow.definition_graph",
+            {item.name for item in manifest.provides_interfaces},
+        )
+        self.assertIn(
+            DEFINITION_READ_SCOPE,
+            {item.scope for item in manifest.permissions},
+        )
+        self.assertIn(
+            DEFINITION_WRITE_SCOPE,
+            {item.scope for item in manifest.permissions},
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()