Extracted duplicate bd command execution pattern from mailbox.go and
router.go into a new helper function in bd.go. This reduces code
duplication and provides consistent error handling via the bdError type.
Changes:
- Added internal/mail/bd.go with runBdCommand helper and bdError type
- Refactored 5 functions in mailbox.go to use runBdCommand
- Refactored 5 functions in router.go to use runBdCommand
- Net reduction of 55 lines of code
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>