RAW (DNG) processing crashed on ImageMagick's deprecated ufraw-batch
delegate, which fails on modern formats such as iPhone ProRAW DNG.
Root cause: the dcraw_emu (LibRaw) decode tier read the wrong output path.
dcraw_emu APPENDS the output extension (raw-in-X.dng -> raw-in-X.dng.tiff)
but the code looked for raw-in-X.tiff (replaced extension), so readFile threw
on every RAW, the tier silently fell through to ufraw, and the 24MB TIFF
leaked into the temp dir on each attempt.
- Repair the dcraw_emu output path; clean it up in finally (fixes the leak)
- Prefer LibRaw full decode over embedded-preview extraction so a
full-resolution RAW is never silently returned as a reduced-size preview
(sample DNG: was 1024x683 preview, now 3474x2314 full)
- Add RAW decode regression tests (DNG full-resolution + all 6 RAW formats);
these were absent, which let the bug ship
- Install libraw-bin on CI test runners so dcraw_emu is actually exercised
