refactor(db)!: finalize pooled WNDB v2 migration

tests/api/test_model_import_endpoints.py

@@ -1,7 +1,9 @@
+import asyncio
 from types import SimpleNamespace
 from unittest.mock import AsyncMock
 from uuid import uuid4
 
+import pytest
 from fastapi import HTTPException
 from fastapi.testclient import TestClient
 
@@ -12,6 +14,7 @@ from app.auth.metadata_dependencies import (
 )
 from app.infra.db.metadb.repositories.metadata_repository import ProjectDbRouting
 from app.infra.db.project_routing import get_project_pgconn_string
+from app.native.wndb.core.database import MaterializedViewRefreshAfterCommitError
 from tests.conftest import build_test_app
 
 
@@ -144,3 +147,47 @@ def test_model_update_uses_project_business_routing(monkeypatch):
         "dsn": "postgresql://user:password@biz.example/routed_business",
     }
     repo.get_project_db_routing.assert_awaited_once_with(project_id, "biz_data")
+
+
+def test_gb18030_upload_is_normalized_to_utf8() -> None:
+    content = "[TITLE]\n天津供水\n[JUNCTIONS]\n".encode("gb18030")
+
+    class FakeUpload:
+        filename = "model.inp"
+
+        async def read(self, _limit: int) -> bytes:
+            return content
+
+    normalized, filename = asyncio.run(model_import._read_upload(FakeUpload()))
+
+    assert filename == "model.inp"
+    assert normalized.decode("utf-8") == "[TITLE]\n天津供水\n[JUNCTIONS]\n"
+
+
+def test_model_update_runs_blocking_import_in_threadpool(monkeypatch) -> None:
+    calls: list[tuple[object, tuple[object, ...]]] = []
+
+    async def fake_threadpool(function, *args):
+        calls.append((function, args))
+
+    monkeypatch.setattr(model_import, "run_in_threadpool", fake_threadpool)
+
+    asyncio.run(model_import._update_from_inp(b"[TITLE]\n", "demo"))
+
+    assert calls == [(model_import._update_from_inp_sync, (b"[TITLE]\n", "demo"))]
+
+
+def test_committed_refresh_failure_is_not_wrapped_as_retryable_500(
+    monkeypatch,
+) -> None:
+    error = MaterializedViewRefreshAfterCommitError("demo")
+
+    async def fail_update(_content: bytes, _project_code: str) -> None:
+        raise error
+
+    monkeypatch.setattr(model_import, "_update_from_inp", fail_update)
+
+    with pytest.raises(MaterializedViewRefreshAfterCommitError) as exc_info:
+        asyncio.run(model_import._apply_model_update(b"[TITLE]\n", "demo"))
+
+    assert exc_info.value is error