Add single-command LLM connection probe

tests/test_connection_test.py

@@ -0,0 +1,24 @@
+import json
+import pytest
+import viano_bug_analysis.connection_test as connection
+from viano_bug_analysis.llm import ProviderResponse, ProviderUnavailable
+from test_llm_gateway import Adapter, provider
+from viano_bug_analysis.llm import GatewayConfig, LLMGateway
+
+
+@pytest.mark.parametrize("response,status", [
+    (ProviderResponse({"answer": "ok"}, "fixture", 1, 1), "SUCCESS"),
+    (ProviderUnavailable("LLM_HTTP_TEMPORARY", http_status=503), "UNAVAILABLE"),
+])
+def test_one_round_no_workspace_files(tmp_path, monkeypatch, capsys, response, status):
+    adapter = Adapter({"first": response})
+    gateway = LLMGateway(GatewayConfig((provider(),)), {"fixture": adapter})
+    monkeypatch.setattr(connection, "preflight", lambda path: gateway)
+    monkeypatch.chdir(tmp_path)
+    exit_code = connection.main([])
+    result = json.loads(capsys.readouterr().out)
+    assert result["status"] == status
+    assert exit_code == (0 if status == "SUCCESS" else 2)
+    assert adapter.calls == ["first"] and not list(tmp_path.iterdir())
+    if status == "UNAVAILABLE":
+        assert result["attempts"][0]["http_status"] == 503