fix(e12): unbreak the gate, and stop printing a command that can strand the restore

Round five. 47 -> 34 -> 15 -> 7 -> 6 raw findings, and this round's sharpest was the
loop's own blind spot: **the branch did not pass the gate.** `prettier --check` is one of
its eight lanes and I had been running the other seven, so an unformatted `onError` from
round one sat on the branch for four rounds — `siftlode publish` would have refused it,
with no --skip flag to get past.

**The restart hint could still strand the restored data.** Round four said the scripts no
longer print a command they cannot resolve; they did. The COMPOSE_FILE fallback only fires
when `docker-compose.yml` is ABSENT, so in a source checkout it never fires and the hint
expanded to a bare, pasteable `docker compose up -d` — which reads the other file, whose
volumes are `pgdata`/`downloads` rather than `siftlode_pgdata`/`siftlode_downloads`, and
recreates the database on an empty one. When the file is unresolved the scripts now print
`-f <the compose file you started with>`: not runnable, which is the point.

**A comment naming the wrong owner.** `formats.py` still said a zero budget is "a refusal
for enqueue to make" — the premise round one disproved, three files away from the two
docstrings that now say the opposite. Anyone acting on it would delete the worker's refusal
and re-open the original inversion, so it now says where the refusal actually lives.

Also: the reset-flag rule was rewritten in three consecutive rounds and pinned by nothing —
two tests now cover a fragment losing its token, both by a pasted verify link and by
navigating away entirely; `backup.ps1` deletes a partially-copied dump before throwing, the
guard round four gave the docs but not the script it mirrors; and one comment that read as
if the asset were untouched by a line four below it.

Gate green, all eight lanes: ruff, ruff format, 3x tsc, eslint, prettier, knip,
vitest 687, pytest 950.

backend/app/downloads/formats.py

@@ -164,9 +164,12 @@ def build_ydl_opts(
         opts.update(extra)
 
     # SEC-13: hard ceiling on a single download. AFTER the adapter merge, for the same reason
-    # `cookiefile` is — a source adapter must not be able to raise a limit the quota layer set. A
-    # non-positive budget is left unset: "0 bytes left" is a refusal for enqueue to make, not
-    # something to express here as an impossible yt-dlp filter.
+    # `cookiefile` is — a source adapter must not be able to raise a limit the quota layer set.
+    #
+    # A non-positive budget is left unset because 0 is not an expressible yt-dlp filter, NOT because
+    # nothing needs to happen: the worker refuses that job outright before extraction (`_OwnerRefused`
+    # → `quota_exceeded`). Enqueue cannot make that call — it ran while the user was still under the
+    # cap. Delete the worker's refusal and this branch silently uncaps the one user already over it.
     if max_bytes and max_bytes > 0:
         opts["max_filesize"] = max_bytes