bead-tracker-migration — move a beads workspace from bd to br

JSONL is the bridge. bd exports it, br imports it. The DB engines differ (bd can ride Dolt; br is always SQLite) but the issue records are interchange-compatible.

⚠️ Critical Constraints

• Export from bd FIRST, on the source machine, before touching br. Why: br init writes a fresh SQLite DB and will not see bd's Dolt rows. If you init br before exporting, the import has nothing authoritative to merge against.

  • WRONG: br init --prefix bd && br sync --import-only (DB empty, no JSONL yet)
  • CORRECT: bd export --all > .beads/issues.jsonl THEN br init THEN import.

• Preserve the ID prefix exactly. Why: issue IDs (bd-abc123) are embedded in commits, dependency links, and chat history. A new prefix orphans every reference.

  • WRONG: br init --prefix br
  • CORRECT: br init --prefix bd (match whatever bd used).