Follow-up to #498. The toggle reached zip downloads but single-photo
downloads still landed on disk with the renamed `event_individual_NNN.jpg`
even when the admin had flipped the setting on. Two reasons, fixed
in lockstep:
- Frontend overrode the server's Content-Disposition with a hardcoded
`<a download="X">` attribute (`gallery.service.ts`, `photos.service.ts`)
where X was the sanitized `photo.filename` known to the client. So
the backend's correctly-formed `Content-Disposition` never reached
the disk write. Added `parseContentDispositionFilename` (RFC 5987 +
plain `filename=` fallback) and let the server name win when present.
- `secureImages.js` (enhanced/maximum protection's secure-download
route) was missed in #498 and still emitted a hardcoded
`filename="${photo.filename}"` regardless of the toggle. Wired it
through `getUseOriginalFilenames` + `buildContentDisposition` so it
matches the regular gallery download path.
Also exposed `Content-Disposition` via CORS so split (cross-origin)
frontend deployments can still read it from JavaScript. Same-origin
Docker deploys already had access; this is a defensive addition for
the split case.
Paul Nothaft
38343e62de