fix: ruff findings

src/fenris/collect.py

@@ -27,7 +27,7 @@ if VENV_DIR.exists():
         if site_packages:
             sys.path.insert(0, str(site_packages))
 
-from fenris.collector import run_collection
+from fenris.collector import run_collection  # noqa: E402 -- must follow the sys.path bootstrap above
 
 
 CONFIG_PATH = Path("/etc/fenris/fenris.conf")

src/fenris/day_aggregate.py

@@ -9,7 +9,7 @@ usage-habit classification is known rather than unknown (§5.3).
 """
 import sqlite3
 from dataclasses import dataclass
-from datetime import datetime, timedelta, timezone
+from datetime import datetime, timedelta
 
 
 @dataclass(frozen=True)

src/fenris/derive.py

@@ -12,7 +12,7 @@ No proportional allocation, endpoint assignment, or double counting.
 """
 import sqlite3
 from datetime import datetime, timedelta, timezone
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional
 
 from .hour_classify import classify_hour, HourSplit
 

src/fenris/init_system.py

@@ -26,7 +26,6 @@ Runit guarantees:
 Spec: §8.4, §8.5, §8.6, §8.7, §8.8, ADR 0008
 """
 import os
-import shutil
 import subprocess
 import sys
 from enum import Enum

src/fenris/legacy.py

@@ -18,11 +18,10 @@ import logging
 import sqlite3
 from datetime import datetime, timezone
 from pathlib import Path
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional
 
 from .hour_classify import classify_hour
-from .segment import open_segment, normalize_identity
-from .monitoring_periods import close_period
+from .segment import open_segment
 
 logger = logging.getLogger(__name__)
 

src/fenris/monitor.py

@@ -31,13 +31,13 @@ if VENV_DIR.exists():
         if site_packages:
             sys.path.insert(0, str(site_packages))
 
-from fenris.store import init_store, get_store_path
-from fenris.monitoring_periods import (
+from fenris.store import init_store  # noqa: E402 -- must follow the sys.path bootstrap above
+from fenris.monitoring_periods import (  # noqa: E402 -- sys.path bootstrap above
     ensure_period_open,
     close_period,
     get_open_period,
 )
-from fenris.init_system import (
+from fenris.init_system import (  # noqa: E402 -- sys.path bootstrap above
     enable_timer,
     disable_timer,
     collect_now,

src/fenris/projection.py

@@ -24,9 +24,9 @@ Criteria: PR-1–PR-17, CI-4.
 """
 import sqlite3
 from dataclasses import dataclass, field
-from datetime import datetime, timedelta, timezone
+from datetime import datetime, timedelta
 from enum import Enum
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional
 
 from .monitoring_periods import interval_within_one_monitoring_period
 

src/fenris/repair.py

@@ -13,11 +13,11 @@ Contracts:
 """
 import logging
 import sqlite3
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from datetime import datetime, timedelta, timezone
 from typing import Optional, List, Tuple
 
-from .derive import find_previous_sample, derive_hours_from_interval, _parse_ts
+from .derive import derive_hours_from_interval, _parse_ts
 
 logger = logging.getLogger(__name__)
 

src/fenris/segment.py

@@ -17,7 +17,6 @@ import sqlite3
 from datetime import datetime
 from typing import Any, Dict, Optional, Tuple
 
-from .collector import normalize_identity
 
 
 def find_current_segment(conn: sqlite3.Connection) -> Optional[Dict[str, Any]]:

src/fenris/status.py

@@ -15,15 +15,14 @@ Criteria: LC-9, CI-2, CI-4, FL-4, FL-5, FL-7.
 """
 import sqlite3
 from contextlib import contextmanager
-import sys
-from datetime import datetime, timedelta, timezone
+from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any, Dict, Iterator, List, Optional, Tuple, TYPE_CHECKING
 
 if TYPE_CHECKING:
     from .status_composition import StatusComposition
 
-from .projection import compute_projection, ConfidenceState, DISCLOSURES
+from .projection import compute_projection, DISCLOSURES
 from .store import SCHEMA_VERSION
 from .init_system import (
     query_service_state as _init_query_service_state,

src/fenris/status_composition.py

@@ -11,25 +11,20 @@ Freshness grading uses shared constants from status.py.
 import enum
 import sqlite3
 from dataclasses import dataclass, field
-from datetime import datetime, timedelta, timezone
+from datetime import datetime, timezone
 from typing import Any, Dict, List, Optional
 
-# Status poll interval (AC78-6): lightweight 5s systemctl show poll
-STATUS_POLL_INTERVAL_S = 5
-
 from .status import (
-    FRESH_THRESHOLD_S,
-    STALENESS_THRESHOLD_S,
     grade_freshness,
     freshness_age_human,
     is_deliberately_paused,
     monitoring_continuity,
     deliberate_pause_lines,
-    open_store_readonly,
-    StoreFault,
-    NewerSchema,
 )
 
+# Status poll interval (AC78-6): lightweight 5s systemctl show poll
+STATUS_POLL_INTERVAL_S = 5
+
 
 # ---------------------------------------------------------------------------
 # Status state enum with glyph and label

src/fenris/store.py

@@ -7,7 +7,6 @@ This module handles:
 """
 import sqlite3
 from pathlib import Path
-from typing import Optional
 
 
 # Schema version - increment on each migration

src/fenris/tui.py

@@ -12,7 +12,6 @@ Criteria: TUI-1, TUI-2, TUI-4, CI-1, CI-2, CI-4, IN-3, LC-6, LC-8.
 from __future__ import annotations
 
 import sqlite3
-import sys
 from datetime import date, datetime, timedelta, timezone
 from pathlib import Path
 from typing import Any, Callable, Dict, List, Optional
@@ -21,7 +20,7 @@ from zoneinfo import ZoneInfo
 from rich.text import Text
 from textual.app import App, ComposeResult
 from textual.binding import Binding
-from textual.containers import Container, Horizontal, VerticalScroll
+from textual.containers import Container, VerticalScroll
 from textual.screen import ModalScreen
 from textual.message import Message
 from textual.widget import Widget
@@ -38,16 +37,14 @@ from .activity_plot import VolumePoint, volume_plot
 from .projection import (
     ConfidenceState,
     ProjectionResult,
-    ScenarioRange,
     compute_projection,
 )
 from .status import (
     CADENCE_DEFAULT_S,
-    FRESH_THRESHOLD_S,
-    STALENESS_THRESHOLD_S,
+    FRESH_THRESHOLD_S,  # noqa: F401 -- re-exported; tests/test_acceptance_sweep.py asserts parity with status
+    STALENESS_THRESHOLD_S,  # noqa: F401 -- re-exported (see above)
     format_disclosures,
-    freshness_age_human,
-    grade_freshness,
+    grade_freshness,  # noqa: F401 -- re-exported (see above)
     deliberate_pause_lines,
     read_status,
     _journalctl_hint,
@@ -55,7 +52,6 @@ from .status import (
 from .status_composition import (
     StatusComposition,
     render_status_tui,
-    STATUS_POLL_INTERVAL_S,
 )
 from .control import MONITOR_HELPER, MonitorError, run_monitor
 from .derive import _parse_ts
@@ -1110,10 +1106,10 @@ def _query_local_day_graph_data(
         (start_text, end_text, selected_date or ""),
     ).fetchall()
     recorded_zones: Dict[str, list[str]] = {}
-    for local_date, timezone in rows:
+    for local_date, zone_name in rows:
         recorded_zones.setdefault(local_date, [])
-        if timezone not in recorded_zones[local_date]:
-            recorded_zones[local_date].append(timezone)
+        if zone_name not in recorded_zones[local_date]:
+            recorded_zones[local_date].append(zone_name)
 
     result: List[Dict[str, Any]] = []
     for local_date in sorted(local_dates):
@@ -1138,9 +1134,9 @@ def _query_local_day_graph_data(
             })
             continue
 
-        for timezone in timezones:
+        for zone_name in timezones:
             summary = query_local_day_summary(
-                conn, local_date, timezone, now,
+                conn, local_date, zone_name, now,
             )
             if summary is None:
                 continue

src/fenris/tz_util.py

@@ -5,7 +5,7 @@ computation used by local-day derivation. All functions are
 stateless and safe to call from the collector and TUI reader.
 """
 import os
-from datetime import datetime, timezone
+from datetime import datetime
 from pathlib import Path