revert(pipeline): back out picture-lock trimming from the preview build

Production fallout after enabling it: the trimmed EXR footage started
after the head handle as intended, but the overlay's burn-in timecode
(hardcoded to start at frame 1001) did not shift with it, so the
delivered burn-in no longer matched the footage. The picture-lock
reference render also never worked correctly in practice. Reverts the
AE panel checkbox, the preview-build script's trim/reference logic, and
the server/worker plumbing around it back to their pre-feature state
(82dfaee) — untrimmed previews, no picture-lock reference, overlay
timecode correct again.

The noPictureLock/piclockRefKey schema columns and their migration are
deliberately left in place: they're already applied in production, and
dropping an applied migration's file risks the next `prisma migrate
deploy`. They sit unused and harmless until this is revisited.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/api/ext/render/jobs/[jobId]/artifact-presign/route.ts

@@ -16,7 +16,6 @@ const KIND_FOLDERS: Record<string, string> = {
   thumbnail: "image",
   metadata: "renders",
   log: "renders",
-  piclockRef: "videos",
 };
 
 export async function POST(