`fit` to the source's own size copies the whole picture (`resize` returns a clone). The raw path
called it unconditionally, so every full-size decode (an export, and its denoised twin) made a
second float RGB buffer: 288 MB and 160 ms at 24 MP, ~390 MB and 225 ms at 33 MP. The JPEG and
preview paths in the same file already fit only when the picture is larger than `max_edge`.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>