{
  "schema": "MKN027_VISIBLE_CHECK_RULES_v1",
  "rules": [
    "schema_version required",
    "revision/base identities required and revision IDs unique",
    "stale base must branch/preserve, never overwrite",
    "missing required alt or invalid heading cannot coexist with PASS accessibility/validation",
    "preview revision must equal selected review revision",
    "publish requires approved review and no unresolved conflict/failed validation",
    "new v2 block requires version-aware migration/compatibility path",
    "historical revisions are immutable",
    "audit evidence required"
  ]
}