ADR-0087 exemption (no-migration-prescription): No authorable key is renamed, retired or re-typed: `nodes[].id` keeps its name, its type and its describe at every depth, and every flow whose node ids are unique across the whole flow parses byte-identically. The only newly refused shape is a region node (`loop.config.body`, `try_catch.config.try` / `.catch`, `parallel.config.branches[]`, at any depth) carrying an id that a top-level node or a node in another region already declares — a collision, not a spelling — and its remedy is to rename one of the two (and re-point the edges that meant it), which is authoring intent no `objectstack migrate meta` rewrite can choose for the author. The census over this repository at `83863b2df` (AST scan of `packages/**` and `examples/**`: 972 outermost literal `nodes[]` arrays including tests, 66 excluding; 102 region arrays / 86 region nodes with a literal id, 15 / 11 excluding tests; a planted region-reuses-top-level-id control reads 1 at its planted line) found zero cross-region or region-vs-top-level collisions, so there is no in-repo file to name.