Commands return errors instead of expect()/unreachable!() (book, library,
undo/redo, paste, find/replace, Pathfinder, tables, QR, select, swatches,
anchors, articles, transform again, XML import). The sample document builder
propagates errors. Commands that add a key to their parameters no longer
panic when a caller (control channel, MCP, script) passes an array or a
string, and corrupt crash-recovery metadata is ignored. engine, mcp and
tools now deny unwrap/expect/panic/unimplemented/todo/unreachable.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>