createBoard fills or mints a .kanban (or extension-less) folder and
refuses to clobber an existing board; createLane/createCard mint fresh
lowercase-UUIDv4 folders and append at max+1024 among visible siblings
via the same strict scan renumber uses (extracted, shared). New files
carry schema/title?/order?/created/modified — created==modified, no
modified-by — written LF through the same atomic temp+rename path.
The editability pre-flight is now scoped to operations that rewrite
siblings: renumber refuses on an uneditable sibling, a create beside
one proceeds. Schema constant unified on BoardLoader.supportedSchema.
Info.plist declares the .kanban document type (UTI conforming to
com.apple.package) so Finder treats a board as one document.
20 new unit tests; 196 total green.
Claude-Session: https://claude.ai/code/session_018BjQRYBR6jQja3jCRi5S3A