feat: serialize official record imports

apps/api/tests/test_api.py

@@ -10,6 +10,7 @@ from sqlalchemy.pool import StaticPool
 
 from app.database import Base, get_session
 from app.community_importer import stage_observations
+from app.importer import ImportAlreadyRunning
 from app.main import app
 from app.models import Bait, BaitKind, CatchReport, ExternalEntityAlias, ExternalObservation, Fish, ImportStatus, ModerationEvent, ModerationStatus, OfficialRecordImport, SourceType, Spot, Waterbody
 
@@ -186,6 +187,12 @@ def test_admin_can_start_and_list_official_import(monkeypatch) -> None:
     listed = client.get("/api/v1/admin/imports?limit=1&offset=0", headers=headers)
     assert listed.status_code == 200
     assert listed.json()[0]["id"] == started.json()["id"]
+    def busy_import(*args, **kwargs):
+        raise ImportAlreadyRunning("official import is already running")
+
+    monkeypatch.setattr("app.main.import_records", busy_import)
+    conflict = client.post("/api/v1/admin/imports/official-records", headers=headers)
+    assert conflict.status_code == 409
 
 
 def test_pending_report_accepts_one_validated_screenshot(monkeypatch) -> None: