Add new `bd rename <old-id> <new-id>` command that:
- Updates the issue's primary ID
- Updates text references in other issues (title, description, etc.)
- Handles dependencies via storage layer's UpdateIssueID
Also fix sync.go build error where hasSyncBranchConfig/syncBranchName
were referenced but not defined - should use sbc.IsConfigured()/sbc.Branch.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
d72f37551b