deterministic input/output hints for interface capabilities

tests/test_candidate_graph.py

@@ -55,6 +55,8 @@ def test_candidate_generator_builds_review_seed_from_observed_facts():
     interface_capability = ability.capabilities[0]
     assert interface_capability.name == "Expose Repository Interface"
     assert interface_capability.confidence == 0.75
+    assert interface_capability.inputs == ["HTTP request"]
+    assert interface_capability.outputs == ["HTTP response"]
     assert interface_capability.features[0].type == "API"
     assert interface_capability.features[0].name == "POST /classify"
     assert interface_capability.features[0].location == "app.py"
@@ -180,5 +182,29 @@ def test_candidate_generator_names_cli_features_from_nearby_function():
     graph = CandidateGraphGenerator().generate(repository, facts, chunks)
 
     feature = graph[0].capabilities[0].features[0]
+    capability = graph[0].capabilities[0]
     assert feature.type == "CLI"
     assert feature.name == "CLI command import_repositories"
+    assert capability.inputs == ["CLI arguments"]
+    assert capability.outputs == ["command output"]
+
+
+def test_candidate_generator_uses_generic_io_for_unknown_interfaces():
+    repository = Repository(
+        id=1,
+        name="UnknownInterface",
+        url="/tmp/unknown-interface",
+        description=None,
+        branch="main",
+        status="analyzed",
+    )
+    facts = [
+        fact(1, "documentation", "README", "README.md"),
+        fact(2, "interface", "possible surface", "src/plugin.py"),
+    ]
+
+    graph = CandidateGraphGenerator().generate(repository, facts)
+
+    capability = graph[0].capabilities[0]
+    assert capability.inputs == ["caller input"]
+    assert capability.outputs == ["callable interface result"]