- New crate filmcraft-format (L3): files are an envelope {format, schema_version, generator,
project}; a chain of single-step JSON migrations (v1 bare Project → v2 envelope) upgrades old
files on load; newer-than-supported files are refused with a clear "update FilmCraft" error;
damaged/foreign files report as such.
- atomic_write: temp file in the same dir + fsync + rename + dir fsync; used for every project
write (FsServices), so a crash mid-save never corrupts the project.
- Engine: file.save/saveAs/open go through the format crate; new file.saveCopy (Save a Copy…,
Cmd+Alt+S) and file.revert; the first save over an upgraded file keeps
"<name> (schema vN backup).fcproj". Project.version dropped (the envelope carries it).
- Hand-made v1 fixtures (minimal + edit without later serde-default fields) in
crates/format/tests/fixtures; 2,000-clip encode/decode timing test.
- docs/project-files.md.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
