The POST /conform route was inserting into the jobs table with non-existent
columns (project_id, metadata) and an invalid enum value ('pending'). Since
GET /jobs reads entirely from BullMQ, the DB insert was both incorrect and
redundant. Now we just enqueue the BullMQ job and return its ID.
GET /api/v1/jobs now queries the proxy, thumbnail, and conform BullMQ
queues directly and returns normalized job objects with id, type,
status, progress, asset_id, timestamps, and error fields.
Also adds DELETE /:id to remove completed/failed jobs from the queue,
supporting the clearCompleted action in jobs.html.
The PostgreSQL jobs table is still used only for conform job creation
(POST /conform) to preserve that workflow.
