Add live acceptance smoke validation

backend/tests/test_artifacts.py

@@ -0,0 +1,34 @@
+from pathlib import Path
+
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def test_project_var_artifact_path_is_served(tmp_path, monkeypatch):
+    from app import main
+
+    project_root = tmp_path / "project"
+    source_root = tmp_path / "source"
+    artifact = project_root / "var" / "uploads" / "datasets" / "case" / "labels" / "label.txt"
+    artifact.parent.mkdir(parents=True)
+    artifact.write_text("ok", encoding="utf-8")
+    source_root.mkdir()
+
+    original = main.settings
+    patched = type(original)(
+        project_root=project_root,
+        source_root=source_root,
+        db_path=original.db_path,
+        log_dir=original.log_dir,
+        weights_root=original.weights_root,
+        task_conda_env=original.task_conda_env,
+        backend_conda_env=original.backend_conda_env,
+        weight_mode=original.weight_mode,
+        enable_shell_tasks=original.enable_shell_tasks,
+    )
+    monkeypatch.setattr(main, "settings", patched)
+
+    response = TestClient(app).get("/api/artifacts/var/uploads/datasets/case/labels/label.txt")
+    assert response.status_code == 200
+    assert response.text == "ok"