ADR-0087 exemption (no-migration-prescription): A regex widening on one declared key of `PluginSchema`, plus the removal of a runtime filter that had excluded that key from an existing check. No metadata key, spec symbol, Zod schema, object definition or stored representation is added, removed or given a different name, so `objectstack migrate meta` has nothing to visit and there is no tombstone to mint. Stored metadata is untouched; what moves is which plugin OBJECTS a boot accepts — strictly more of them at the schema, and on `LiteKernel` the malformed-`version` objects `ObjectKernel` already refused. The channel that reaches an affected plugin author is the refusal itself, which names the plugin and the offending key at `use()`, and which value a malformed `version` should carry is authoring intent no ledger entry can decide.