fix: ruff findings

tests/test_issue_93.py

@@ -11,7 +11,6 @@ Seams:
 - Read side: query_local_day_history() returns entries with evidence flags
 - Repair: repair_derivation() does not touch existing local_days
 """
-import sqlite3
 from datetime import datetime, timedelta, timezone
 from pathlib import Path
 from typing import Any, Dict
@@ -21,7 +20,7 @@ import sys
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
 
-from fenris.store import init_store, SCHEMA_VERSION
+from fenris.store import init_store
 from fenris.local_day import (
     derive_local_day_summary,
     persist_local_day,
@@ -29,11 +28,9 @@ from fenris.local_day import (
     query_local_day_history,
     LocalDaySummary,
     LocalDayHistoryEntry,
-    _is_detail_available,
 )
-from fenris.pruning import prune_old_samples, RAW_SAMPLE_RETENTION_DAYS
+from fenris.pruning import prune_old_samples
 from fenris.repair import repair_derivation
-from fenris.monitoring_periods import ensure_period_open, close_period
 
 
 # ---------------------------------------------------------------------------
@@ -226,7 +223,7 @@ class TestBoundaryPreservation:
         _insert_sample(conn, "2026-09-16T23:55:00+00:00", bw=100)
         _insert_sample(conn, "2026-09-17T12:30:00+00:00", bw=200)
 
-        pruned = prune_old_samples(conn, now, retention_days=14)
+        prune_old_samples(conn, now, retention_days=14)
 
         # Boundary anchor should be retained
         cursor = conn.execute(
@@ -305,7 +302,6 @@ class TestLegacyDataHandling:
     def test_incomplete_legacy_labelled_correctly(self, tmp_path):
         """Legacy summary without full evidence is labelled incomplete."""
         conn = init_store(tmp_path / "obs.db")
-        now = datetime(2026, 10, 1, 12, 0, 0, tzinfo=timezone.utc)
 
         # Simulate a legacy summary that can't establish a full local-day total
         legacy = LocalDaySummary(