feat: expand import ingestion workflow with staging previews, transactional commits, and new API tests

tests/test_import_api.py

@@ -0,0 +1,70 @@
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from models.project import MiningOperationType, Project
+from models.scenario import Scenario, ScenarioStatus
+
+
+def test_project_import_preview_and_commit_flow(
+    client: TestClient,
+    unit_of_work_factory,
+) -> None:
+    with unit_of_work_factory() as uow:
+        assert uow.projects is not None
+        existing = Project(
+            name="Existing Project",
+            location="Chile",
+            operation_type=MiningOperationType.OPEN_PIT,
+        )
+        uow.projects.create(existing)
+
+    csv_content = (
+        "name,location,operation_type\n"
+        "Existing Project,Peru,underground\n"
+        "New Project,Canada,open pit\n"
+    )
+
+    preview_response = client.post(
+        "/imports/projects/preview",
+        files={"file": ("projects.csv", csv_content, "text/csv")},
+    )
+    assert preview_response.status_code == 200
+    preview_data = preview_response.json()
+    assert preview_data["summary"]["accepted"] == 2
+    token = preview_data["stage_token"]
+    assert token
+
+    commit_response = client.post(
+        "/imports/projects/commit",
+        json={"token": token},
+    )
+    assert commit_response.status_code == 200
+    commit_data = commit_response.json()
+    assert commit_data["summary"] == {"created": 1, "updated": 1}
+
+    with unit_of_work_factory() as uow:
+        assert uow.projects is not None
+        projects = {project.name: project for project in uow.projects.list()}
+        assert "Existing Project" in projects and "New Project" in projects
+        assert (
+            projects["Existing Project"].operation_type
+            == MiningOperationType.UNDERGROUND
+        )
+
+    repeat_commit = client.post(
+        "/imports/projects/commit",
+        json={"token": token},
+    )
+    assert repeat_commit.status_code == 404
+
+
+def test_scenario_import_commit_invalid_token_returns_404(
+    client: TestClient,
+) -> None:
+    response = client.post(
+        "/imports/scenarios/commit",
+        json={"token": "missing-token"},
+    )
+    assert response.status_code == 404
+    assert "Unknown scenario import token" in response.json()["detail"]