residue v0.0.1

First release.

• residue scan [PATH...] lists the linked worktrees of each repository at or under PATH, with size, a verdict (candidate, keep, unknown, stale) and the reason for it.
• residue explain PATH shows every check for one worktree, and facts that never block: local-only commits, a gone upstream, the newest change on disk, and size.
• residue remove PATH... prints a plan, asks for confirmation (or accepts --yes), re-checks against a fresh process snapshot, then runs git worktree remove without --force. Branches and commits are kept.
• Activity probe with three states (in_use, not_observed, unknown): lsof on macOS, /proc on Linux.
• Ignored files block removal unless every one matches the regenerable list. Extend the list with ~/.config/residue/regenerable or --regenerable.
• --json output for every command: residue.scan/v1, residue.explain/v1, residue.remove/v1.