wiki-migration

The minimal registry + runner /ren:update (and /ren:doctor's schema-version check) drive migrations through. Per spec §7.1, donor's heavy chain-computer + registry-template + JSON-schema-validated verify-page.sh machinery is pre-excluded for 0.2 — this is deliberately thin.

schemas.json

Enumerates only the page types actually stamped by something in this repo: identity, l2-map (both still at their initial schema, no migrations yet), and routine-spec (schema 3, migrated via routine-spec-1-to-2 then routine-spec-2-to-3). Not a speculative full taxonomy — add an entry only when a page type gets a real migration.

The env-mapping shim (load-bearing)

migrations/routine-spec-1-to-2/ was carried verbatim from donor and expects SF_WIKI_ROOT/SF_SNAPSHOT_DIR. migrations/routine-spec-2-to-3/ was written fresh for this repo and expects REN_WIKI_ROOT/REN_SNAPSHOT_DIR. run_migration() sets both pairs of env vars to the same values on every invocation, so the same thin runner drives either migration directory without needing to know in advance which naming convention its migrate.sh reads. This is documented here rather than fixed at the source, because "carry verbatim" for 1-to-2 was an explicit instruction (Task 6.3) — the shim is the seam, not a bug to clean up.

Behavior

1. load_registry() reads schemas.json.
2. migration_chain(page_type, from_version) returns the ordered subset of that page type's migration directories still needed to reach current.
3. For each directory in the chain: run_migration(migration_dir, page_path, wiki_root, snapshot_dir) invokes its migrate.sh (idempotent, in-place — see each migration's own README for what it changes).
4. verify_page(verify_json_path, page_path) checks the migrated page's frontmatter against that migration's verify.json assertions (yaml.valid/yaml.equals/yaml.present/yaml.in; snapshot.body-identical is not implemented here — callers that need it compare bodies directly, which both migration test suites already do).

What this skill does NOT do

• Compute a full dependency-ordered migration chain across ALL page types with cross-references (donor's chain-computer). This is a flat per-page-type list.
• Validate verify.json files against a JSON Schema. verify_page() is a small, direct predicate interpreter for the four predicate kinds actually used by the two migrations in this repo.
• Decide WHEN to migrate. /ren:update (this skill's only caller) owns the snapshot-before/diff-approval/apply flow around these primitives.

References

• migrations/routine-spec-1-to-2/, migrations/routine-spec-2-to-3/ — the two migration directories this skill can run
• skills/update/ — the only intended caller of run_migration/verify_page
• skills/doctor/ — reads load_registry()/migration_chain() for its schema-version check