refactor(logs): name every logger after its module, and hold it there

25 literal names covered 34 modules. plex/client.py, plex/stream.py,
plex/subtitles.py, plex/sync.py and two Plex route modules all called themselves
`siftlode.plex`; downloads/pipeline.py called itself `siftlode.worker`;
routes/channels.py called itself `siftlode.api`. The `logger` column is in every
stored row so E22.6's console can filter on it, and so an operator can pin a level
to one part of the system — neither works when six modules share a name.

`logs.get_logger(__name__)` derives it: app/plex/sync.py -> siftlode.plex.sync.
One name per module, and it cannot drift from the file it sits in.
tests/test_logger_names.py pins the derivation, that everything stays under the
one `siftlode` tree the handler and the tests attach to, and that no module
hand-rolls a name again unless the line says why (`# logger-name-ok: <why>`).
Two do: get_logger's own call, and `siftlode.http`, which is named for the traffic
it carries rather than the module it lives in — it replaced uvicorn's access log
and is what an operator pins when they want request lines and nothing else.

app/scheduler.py called its logger `logger`; every other module calls it `log`.

ruff gains LOG, G, T20, TRY400, TRY401 and S112. Four findings cleared with them:
worker.py logged `str(exc)[:120]` where the traceback was the whole question, and
three prints/f-strings that are deliberate now say so on the line. S110 and BLE001
stay off until S3 — 23 handlers are outstanding and each is a judgement about one
of them; enabling the rules first would just mean 23 blanket noqas.

backend/app/plex/client.py

@@ -6,16 +6,15 @@ metadata, image proxying, and (P5) optional watch-state write-back. Requests JSO
 ``Accept: application/json`` header (Plex serves XML by default).
 """
 
-import logging
 from urllib.parse import quote
 
 import httpx
 from sqlalchemy.orm import Session
 
-from app import sysconfig
+from app import logs, sysconfig
 from app.config import settings
 
-log = logging.getLogger("siftlode.plex")
+log = logs.get_logger(__name__)
 
 
 class PlexError(Exception):

backend/app/plex/stream.py

@@ -18,7 +18,6 @@ segments. The remux is CPU-light (video copy + a tiny audio transcode), so it ru
 CPU-only prod host; only P3's full transcode is CPU-heavy.
 """
 
-import logging
 import os
 import re
 import secrets
@@ -31,15 +30,14 @@ from pathlib import Path
 
 from sqlalchemy.orm import Session as DbSession
 
-from app import sysconfig
+from app import logs, sysconfig
 from app.config import settings
 from app.downloads.edit import encode_thread_cap
 from app.models import PlexItem
 from app.plex import paths
 from app.plex.sync import HW_DECODABLE_CODECS
 
-log = logging.getLogger("siftlode.plex")
-
+log = logs.get_logger(__name__)
 _HLS_ROOT = (
     Path(settings.plex_hls_dir)
     if settings.plex_hls_dir

backend/app/plex/subtitles.py

@@ -33,7 +33,6 @@ zero-based clock and shifted back to absolute time here with `shift_vtt`.
 """
 
 import json
-import logging
 import re
 import subprocess
 import tempfile
@@ -44,6 +43,7 @@ from pathlib import Path
 
 from sqlalchemy.orm import Session
 
+from app import logs
 from app.db import SessionLocal
 from app.models import PlexItem
 from app.plex import paths as plex_paths
@@ -51,8 +51,7 @@ from app.plex.cache import CACHE_DIR
 from app.plex.client import PlexClient, PlexError
 from app.plex.lookups import by_rating_key
 
-log = logging.getLogger("siftlode.plex")
-
+log = logs.get_logger(__name__)
 # Image-based subtitle codecs (Blu-ray/DVD) — can't be turned into text WebVTT (would need burn-in).
 BITMAP_SUBS = {
     "pgs",

backend/app/plex/sync.py

@@ -15,20 +15,18 @@ dead `enabled` column) is a separate follow-up. Cast + intro/credit markers are
 item-detail/player path (P2), not here.
 """
 
-import logging
 from datetime import datetime, timezone
 
 from sqlalchemy import func, select
 from sqlalchemy.orm import Session
 
-from app import sysconfig
+from app import logs, sysconfig
 from app.models import PlexCollection, PlexItem, PlexLibrary, PlexSeason, PlexShow
 from app.plex import detail, people
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
 from app.plex.lookups import by_rating_key
 
-log = logging.getLogger("siftlode.plex")
-
+log = logs.get_logger(__name__)
 # Codecs/containers a browser can play in a native <video> without any transcoding.
 _BROWSER_VIDEO = {"h264"}
 _BROWSER_AUDIO = {"aac", "mp3", "opus", "vorbis"}

backend/app/plex/tmdb.py

@@ -10,7 +10,6 @@ One-parser rule (mirrors app/plex/detail.py): `parse_tmdb` is the pure parser, `
 the row. The enrich batch + scheduler entry live here too so the whole TMDB integration is one module.
 """
 
-import logging
 import time
 from datetime import datetime, timezone
 
@@ -19,12 +18,11 @@ from sqlalchemy import func, select
 from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.orm import Session
 
-from app import sysconfig
+from app import logs, sysconfig
 from app.config import settings
 from app.models import PlexItem, PlexPerson, PlexShow
 
-log = logging.getLogger("siftlode.tmdb")
-
+log = logs.get_logger(__name__)
 # Politeness throttle: TMDB tolerates ~50 req/s; ~33/s leaves comfortable headroom for a shared host.
 _MIN_INTERVAL = 0.03
 

backend/app/plex/watch_sync.py

@@ -17,14 +17,13 @@ and the incremental pull resolves a genuine divergence to Plex's state (see `_pu
 running a last-write-wins comparison.
 """
 
-import logging
 from datetime import datetime, timezone
 
 from sqlalchemy import func, select, update
 from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.orm import Session
 
-from app import sysconfig
+from app import logs, sysconfig
 from app.db import SessionLocal
 from app.models import PlexItem, PlexLink, PlexState
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
@@ -36,8 +35,7 @@ from app.plex.sync import (
     _paginate,
 )
 
-log = logging.getLogger("siftlode.plex.watch")
-
+log = logs.get_logger(__name__)
 # A resume position below this many seconds isn't worth mirroring — matches the player's own
 # _PROGRESS_MIN_S (a stray few-second seek is not "in progress").
 _PROGRESS_MIN_S = 5