macOS hands files opened from Finder, the Dock or open -a to the application delegate's application:openURLs:, which winit's delegate lacks, so AppKit showed "SolidCraft cannot open files in the SolidCraft design format". open_documents adds that method to the delegate's class before launch finishes and queues the paths for the UI, which opens them like files named on the command line.
This is the one place SolidCraft's own code uses unsafe: the app crate denies unsafe_code instead of forbidding it, and only the two macOS-only functions in open_documents.rs allow it, with the reason documented there and in AGENTS.md. Adapted from VectorCraft (see ATTRIBUTION.md).
Closes#997.
Corrects the modeling skill: an edge of the face a shell removes is rounded after the shell, a slot along Y is dimensioned horizontally, long shallow arcs measure to about 0.1%, and a boolean retry warning can hide wrong geometry when the volume does not match.