BlockInputKit

Add or extend support for a BlockInputKit block type. Use when the user asks to add a new block kind/type, support a new Markdown block, add editor rendering for a block, make a block selectable/editable/reorderable, implement frontmatter/code/list/quote-like block behavior, or implicitly requests block support through phrases like "add support for X blocks", "new block", "block type", "block kind", "Markdown construct", "editor should handle X", or "render/edit X as a block".

Prepare, dry-run, and publish BlockInputKit Swift package releases. Use when the user asks to release BlockInputKit, run a release dry run, create a patch/minor/major release, push a version tag, or prepare GitHub release notes.