Two bugs surfaced on first dev-server test:
1. /api/staff/file 404s for valid file ids. The old per-org check
read civicrm_entity_file and required entity_id==orgId, but our
upload route anchors files to the submitter's contact id, not the
org's — the entity_file row is metadata-only on this install
(see comment in app/api/upload/route.ts). The custom-field column
is the real ownership signal, which /api/staff/report already uses,
and the staff key already gates org access. Drop the bogus check;
keep the entity_table whitelist as defence.
2. Same-origin PDF iframe blocked by frame-ancestors 'none'. The
strict global CSP excludes /staff/report; add /api/staff/file to
the same embed-friendly profile so the lightbox iframe can load.
Also move the sandbox/default-src 'none' CSP to the attachment path
only — a strict sandbox header breaks Chrome's PDF viewer on inline
responses (it needs to load fonts and plugin-mode rendering). On
inline we rely on the SAFE_INLINE_MIMES allowlist + X-Content-Type-
Options + the app's global CSP.