Problem: Premiere offers OpenEXR as an image-sequence export format;
FilmCraft could not write EXR at all (docs/gaps.md G13).
Fix: a new export format (id exr, "OpenEXR") writing numbered .exr stills,
with a preset, the Include Alpha Channel option, the file.exportMedia format
list and es/ja/zh-cn strings. The writer in crates/export/src/raster.rs
follows the public OpenEXR file layout: version 2 single-part scan-line
file, half-float B/G/R(/A) channels, no compression, one scan line per
chunk, Rec.709 chromaticities; values are scene-linear (the pipeline's
transfer undone) with premultiplied alpha, as EXR defines. No new
dependency. ZIP / PIZ / DWA compression stays open.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>