migrate

Migrate Legacy Index (fallback)

Outcome

A pre-v7 <git-root>/.bonfire/index.md becomes v7.0-compliant: the v1 fence pair appears at the top, the legacy ## In flight heading is renamed to the canonical curated heading (## Notes), the legacy ## Sessions content is moved out to the canonical sidecar (<git-root>/.bonfire/log.md), and everything else in the file is preserved byte-for-byte in its original relative position. Adapters take over auto-updates on the next session without destroying any of the user's prior curation.

When to use this

• One-off, manual trigger: /skill:bonfire migrate (or your host's equivalent).
• After installing Bonfire 7.0+ on a repo whose index.md predates fences. The Pi adapter surfaces this state in two places: the footer shows △ !fences (yellow), and a one-shot notify points at this exact command. The Claude adapter is silent on this state.
• Native adapters never run this automatically. They leave fenceless files alone by design — auto-fencing a curated file would be destructive.

Acceptance Criteria

1. Opt-in respected: <git-root>/.bonfire/ exists. If not, exit silently. (Same gate as end.md.)
2. Per-repo opt-out respected: if <git-root>/.bonfire/config.json has { "auto": false }, exit silently.
3. Idempotent: if both v1 fence pairs are already present and well-formed (<!-- bonfire:auto-inflight:start v1 --> … <!-- bonfire:auto-inflight:end --> and the matching sessions pair), exit silently. Don't re-migrate.
4. Empty-file shortcut: if index.md doesn't exist, or contains only a YAML frontmatter + H1 and no other content, use templates/index.md directly. There's nothing to migrate; just bootstrap.
5. Backup written before rewriting index.md: copy the original to <git-root>/.bonfire/index.md.pre-migrate-YYYY-MM-DD.bak. If that path already exists, append a counter suffix (...-1.bak, ...-2.bak, …). Never overwrite a prior backup.
6. Migrated index.md shape, top-to-bottom:
   1. Optional YAML frontmatter (preserved verbatim if present).
   2. The original H1 (preserved verbatim).
   3. <!-- bonfire:auto-inflight:start v1 --> block with a brief placeholder body explaining the next session will populate it.
   4. <!-- bonfire:auto-sessions:start v1 --> block, empty ## Sessions body.
   5. A horizontal rule (---) separating the auto-managed region from the curated region.
   6. Any free-form prose between the H1 and the first H2 in the original (a "lead paragraph") — preserved verbatim, in its original position relative to surrounding sections (i.e. now between the boundary --- and the next H2).
   7. The original ## In flight content, with the heading renamed to ## Notes — the canonical curated heading.
   8. The original ## Sessions section is removed from index.md (its content is written to log.md, see criterion 7).
   9. Any other H2+ sections from the original file, in their original order, with original headings.
7. Sidecar write for legacy session content:
   • Write the original ## Sessions block (the H2 heading itself plus all entries below it, up to but not including the next H2 or EOF) to <git-root>/.bonfire/log.md.
   • Header prepended to the sidecar: _Migrated from index.md on YYYY-MM-DD_ followed by a blank line, then the H2 + content.
   • Collision handling: if log.md already exists, write to <git-root>/.bonfire/log-pre-migrate-YYYY-MM-DD.md instead (with counter suffix on collision). Never silently overwrite an existing log.md.
   • If the original file has no ## Sessions section, skip the sidecar write entirely (no empty file).
8. Atomic writes: both index.md and the sidecar are written via tmpfile + rename. Don't truncate in place.