Never lose work: atomic saves (temporary file, flush, rename) keeping the replaced version as <file>.bak; autosave of unsaved changes into a recovery folder (every 5 min, preference autosave_minutes, and after commands over 1.5 s; skipped when unchanged; entries locked while their app runs); Recover unsaved design? at launch; doc.recovery_list / doc.recover / doc.recovery_discard; kill-mid-save test

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/io/src/lib.rs

@@ -6,11 +6,13 @@
 #![forbid(unsafe_code)]
 
 mod dxf;
+pub mod safe_write;
 mod sketch2d;
 mod svg;
 mod threemf;
 
 pub use dxf::{read_dxf, write_dxf};
+pub use safe_write::{backup_path, write_atomic};
 pub use sketch2d::{Geom2, MAX_DRAWING_BYTES};
 pub use svg::read_svg;
 pub use threemf::{MAX_3MF_BYTES, MeshObject, model_xml, read_3mf, weld, write_3mf};