files
List Files
List all uploaded files for an agent.
Merges three sources so nothing already on record goes missing:
input artifacts on S3 (this PR), the legacy uploads/{agent}/{file}
S3 key (still real data — 454 objects on the dev bucket, unmigrated),
and local disk (files that never made it to S3 — David’s counts: 214
dev / 60 prod). This endpoint has no session_id, so the S3 input-artifact
lookup is scoped to _shared — the same scope an unsessioned upload
writes to.
