Implements `bd refile <source-id> <target-rig>` which: - Gets source issue via routing - Creates new issue in target rig with same content - Closes source with "Refiled to <new-id>" - Appends "(Refiled from <old-id>)" to description Target rig accepts rig names (beads), prefixes (bd-), or prefix shorthand (bd). 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>