style: apply ruff format across backend + scripts (line-length 100)

Mechanical, whole-tree `ruff format` pass — no behaviour change. Recorded in
.git-blame-ignore-revs (next commit) so git blame skips it.

backend/app/worker.py

@@ -15,6 +15,7 @@ Design:
     yt-dlp download if it's no longer `running`.
   * Crash-safe: on startup, orphaned `running` jobs are requeued and `downloading` assets reset.
 """
+
 import logging
 import os
 import shutil
@@ -53,6 +54,7 @@ def _handle_signal(signum, frame):
 
 # --- claim + recovery -----------------------------------------------------------------------
 
+
 def _wait_for_schema(timeout: float = 300.0) -> bool:
     """Block until the download tables exist before doing any DB work. Returns False if they never
     appeared (or we were asked to stop while waiting).
@@ -74,7 +76,8 @@ def _wait_for_schema(timeout: float = 300.0) -> bool:
                 log.error(
                     "download schema still absent after %ss — the API's migrations have not landed; "
                     "exiting so the container restarts: %s",
-                    timeout, str(exc)[:120],
+                    timeout,
+                    str(exc)[:120],
                 )
                 return False
             log.info("waiting for the database schema (API migrations)…")
@@ -135,9 +138,7 @@ def _claim_job() -> int | None:
             ),
             {"dmc": default_mc},
         ).fetchall()
-        chosen = next(
-            (jid for jid, uid in rows if not quota.at_concurrency_limit(db, uid)), None
-        )
+        chosen = next((jid for jid, uid in rows if not quota.at_concurrency_limit(db, uid)), None)
         if chosen is None:
             db.commit()  # release the row locks; nothing eligible right now
             return None
@@ -308,7 +309,12 @@ def _run_supervised(job_id: int, asset_id: int) -> None:
     except Exception:  # noqa: BLE001 — a watchdog error must NEVER leave the child running unsupervised
         log.exception("supervisor loop failed for job %s; stopping the child", job_id)
         _fail_after_kill(
-            job_id, asset_id, proc, grace_s, "The download was stopped after a worker error.", "unknown"
+            job_id,
+            asset_id,
+            proc,
+            grace_s,
+            "The download was stopped after a worker error.",
+            "unknown",
         )
         return
 
@@ -324,24 +330,37 @@ def _run_supervised(job_id: int, asset_id: int) -> None:
                 if status == "running":
                     _cleanup_staging(asset_id)
                     _set_job(
-                        job_id, status="error", error_code="unknown", phase=None,
+                        job_id,
+                        status="error",
+                        error_code="unknown",
+                        phase=None,
                         error=f"The download process exited unexpectedly (code {proc.returncode}).",
                     )
-                    log.warning("job %s: child exited %s without finishing", job_id, proc.returncode)
+                    log.warning(
+                        "job %s: child exited %s without finishing", job_id, proc.returncode
+                    )
         except Exception:  # noqa: BLE001 — boot recovery is the backstop for a stuck 'running' job
             log.exception("post-exit reconciliation failed for job %s", job_id)
         return
 
     if reason == "stalled":
         _fail_after_kill(
-            job_id, asset_id, proc, grace_s,
-            f"The download stalled (no progress for {int(stall_s)}s) and was stopped.", "network",
+            job_id,
+            asset_id,
+            proc,
+            grace_s,
+            f"The download stalled (no progress for {int(stall_s)}s) and was stopped.",
+            "network",
         )
         return
     if reason == "timeout":
         _fail_after_kill(
-            job_id, asset_id, proc, grace_s,
-            f"The download exceeded the {int(wall_s)}s time limit and was stopped.", "network",
+            job_id,
+            asset_id,
+            proc,
+            grace_s,
+            f"The download exceeded the {int(wall_s)}s time limit and was stopped.",
+            "network",
         )
         return
     # cancelled / abandon / shutdown: stop + free the asset, but leave the job's own DB status.
@@ -349,7 +368,9 @@ def _run_supervised(job_id: int, asset_id: int) -> None:
     if reason == "shutdown":
         _requeue_if_running(job_id, None)  # resume on the next boot
     elif reason == "abandon":
-        log.warning("job %s: killed a child wedged past the wall-clock; DB status left intact", job_id)
+        log.warning(
+            "job %s: killed a child wedged past the wall-clock; DB status left intact", job_id
+        )
     else:  # cancelled
         log.info("job %s: child stopped (route pause/cancel)", job_id)
 
@@ -363,6 +384,7 @@ def _cleanup_staging(asset_id: int) -> None:
 
 # --- processing -----------------------------------------------------------------------------
 
+
 def _process_job(job_id: int) -> None:
     """Dispatch a claimed job. The trivial outcomes (cache hit, dead/contended asset) are handled
     inline and cheaply; the actual heavy work (yt-dlp download / ffmpeg edit) is claimed here and
@@ -423,6 +445,7 @@ def _finish_from_cache(job_id: int, asset_id: int) -> None:
 
 # --- loop -----------------------------------------------------------------------------------
 
+
 def _worker_loop(idx: int) -> None:
     while not _stop.is_set():
         try: