fix(logs): deep-review round 1 — say each failure once, and scrub it everywhere

- yt-dlp's text is scrubbed wherever it is logged, not only in the adapter:
  `formats.log_safe` takes out the URL, the `[extractor] <id>:` prefix and
  file paths, and the job-failed, refused, edit-failed and backfill lines use
  it. Done lines log the asset id, not the title-built path. The PII contract
  now bans `rel`/`rel_path`/`title`.
- A traceback goes with a download/edit failure only when it is our own code
  failing; for yt-dlp's DownloadError, our RuntimeErrors and OSErrors its foot
  is the unscrubbed message.
- yt-dlp's `error` maps to WARNING: it fires on attempts the fallback client
  set recovers from; the job's verdict is `download.job.failed`.
- The sink groups a bare `%s` pass-through by its text (numbers folded), and
  a process's last batch closes the repeat window, so a short-lived download
  child still reports what it dropped.
- Worker-side failures (stall, wall-clock, no asset, cached asset error) log
  `download.job.failed` with a cause; they left no line at all before. The
  crash, supervisor-error and non-zero-exit lines carry the code too.
- An edit failure is one coded line in `_fail_edit`, for every path.
- `logs.get_logger("__main__")` resolves to the `-m` module, so the worker
  and the download child keep their names.
- TRACE lines carrying user content are gated on `logs.consented_trace()`,
  not on the process level; a contract test pins it.
- The OAuth token refresh goes through `_upstream_failure`; transport errors
  carry reason `transport`. Subscribe recognises a duplicate by reason code
  only (the prose fallback was dead).
- Once-only guards for a stale sysconfig override and a refusing HLS session
  directory; item_detail splits Plex failures from our own parse bugs.
- The playlist breaker line names the playlist and the action; comments that
  were false (runner noqa, `_merge_vtt`, sink grouping) are corrected.

backend/app/routes/search.py

@@ -317,8 +317,8 @@ def search_youtube(
                 # themselves, and `redact_text` does not cover it — it scrubs addresses and
                 # credential params, not what someone typed into the search box. What the
                 # ERROR line carries instead is the shape of the failure, which is what tells
-                # an ingest bug from an upstream one; the term follows at TRACE, where the
-                # consent that allows it is the only thing that emits the record at all.
+                # an ingest bug from an upstream one; the term follows at TRACE, and only
+                # under this user's own consent — not whenever the process runs at TRACE.
                 log.exception(
                     "live search ingest failed",
                     extra=logs.event(
@@ -328,12 +328,13 @@ def search_youtube(
                         collected=len(collected),
                     ),
                 )
-                log.log(
-                    logs.TRACE,
-                    "the term the ingest failed on",
-                    # log-pii-ok: TRACE is the consented level, and this is what it is for
-                    extra=logs.event("search.live.term", term=term),
-                )
+                if logs.consented_trace():
+                    log.log(
+                        logs.TRACE,
+                        "the term the ingest failed on",
+                        # log-pii-ok: only under this user's own Teljes consent
+                        extra=logs.event("search.live.term", term=term),
+                    )
                 if collected:
                     break  # keep what earlier pages already gathered
                 raise HTTPException(