feat(pipeline): per-shot client naming alias for slates, overlays, and delivery

Clients sometimes ship footage under a naming convention that doesn't
match our own shot codes. Adds an optional Shot.clientCode, editable on
the Slate tab: when set, it replaces shotCode only in what the client
actually sees — slate identity, overlay burn-in, and delivered EXR/MOV
file and folder names in Netflix packages — with our own version string
flatly appended (no "_cmp_TT_" studio jargon mixed in). Internal render
paths, EXR filenames on the SAN, comp names, and DB lookups are
untouched. Shots without a client code render identically to before.

Delivery packages denormalize clientCode at build time, same as the
existing shotCode/versionString snapshot, so a later shot edit can't
retroactively change already-built delivery history. The worker now
renames delivered EXR frames and the delivery MOV using the existing
frame-number parser (SequencePattern) so only the base name changes —
frame numbers and padding survive exactly. This is the one piece of the
change that could plausibly ship the wrong bytes, so it's covered by
new unit tests (renaming, padding, MOV rename, checksum-survives-rename,
and a graceful fallback for an unparseable frame number) rather than
resting on manual verification alone.

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

prisma/migrations/20260826000000_client_code/migration.sql

@@ -0,0 +1,9 @@
+-- Client naming alias: substituted for shotCode only on slates, overlay
+-- burn-ins, and delivered file/folder names. Internal paths, comp names and
+-- DB lookups always use shotCode.
+
+-- AlterTable
+ALTER TABLE "shots" ADD COLUMN "clientCode" TEXT;
+
+-- AlterTable
+ALTER TABLE "delivery_items" ADD COLUMN "clientCode" TEXT;