style: apply ruff fixes

backend/main.py

@@ -14,12 +14,12 @@ from fastapi.responses import Response
 from fastapi.staticfiles import StaticFiles
 from metrics import observe_request, prometheus_metrics
 from middleware import CorrelationIdMiddleware
+from routes.ask import router as ask_router
 from routes.config import router as config_router
 from routes.events import router as events_router
 from routes.fetch import router as fetch_router
 from routes.fetch import run_fetch
 from routes.health import router as health_router
-from routes.ask import router as ask_router
 from routes.rules import router as rules_router
 from routes.webhooks import router as webhooks_router
 

backend/routes/ask.py

@@ -46,7 +46,9 @@ def _extract_time_range(question: str) -> tuple[str | None, str | None]:
             start = now.replace(hour=0, minute=0, second=0, microsecond=0)
         else:
             num = int(m.group(1))
-            delta = {"days": timedelta(days=num), "hours": timedelta(hours=num), "minutes": timedelta(minutes=num)}[unit]
+            delta = {"days": timedelta(days=num), "hours": timedelta(hours=num), "minutes": timedelta(minutes=num)}[
+                unit
+            ]
             start = now - delta
         return start.isoformat().replace("+00:00", "Z"), now.isoformat().replace("+00:00", "Z")
 
@@ -238,11 +240,7 @@ async def ask_question(body: AskRequest, user: dict = Depends(require_auth)):
     query = _build_event_query(entity, start, end)
 
     try:
-        cursor = (
-            events_collection.find(query)
-            .sort([("timestamp", -1)])
-            .limit(LLM_MAX_EVENTS)
-        )
+        cursor = events_collection.find(query).sort([("timestamp", -1)]).limit(LLM_MAX_EVENTS)
         events = list(cursor)
     except Exception as exc:
         logger.error("Failed to query events for ask", error=str(exc))

backend/tests/test_ask.py

@@ -1,11 +1,7 @@
 from datetime import UTC, datetime, timedelta
 
-import pytest
-from fastapi.testclient import TestClient
-
 from routes.ask import _build_event_query, _extract_entity, _extract_time_range
 
-
 # ---------------------------------------------------------------------------
 # Unit tests: time-range extraction
 # ---------------------------------------------------------------------------
@@ -44,7 +40,7 @@ class TestExtractTimeRange:
     def test_today(self):
         start, end = _extract_time_range("What happened today?")
         start_dt = datetime.fromisoformat(start.replace("Z", "+00:00"))
-        end_dt = datetime.fromisoformat(end.replace("Z", "+00:00"))
+        # end_dt is not needed for this assertion
         # Should be from midnight today to now
         assert start_dt.hour == 0
         assert start_dt.minute == 0