# `degrade`: The Degradation Engine (capability-driven lowering, annotate + report)

```{py:currentmodule} myform.degrade
```

`lower_with_enclaves` immutably rewrites every non-native node through the declarative
`REGISTRY` until the target writer sees only native semantic nodes. Exact target rules override
target-neutral fallbacks; instance preflights refine nominally-native capability entries; every
approximation, replacement, drop, and verified enclosure produces a path/span-addressed
`ConversionReport` entry. A `ConversionArtifact` binds each enclosed report row to one exact
source-occurrence carrier and a writer-recovered final typed marker link; legacy `lower` raises
rather than discard a real carrier. Provenance comments are target-native and remain beside the
affected flow construct when structurally legal.

Extensions receive the same process-wide `REGISTRY`: use `REGISTRY.register`,
`REGISTRY.register_preflight`, and `REGISTRY.register_comment` to extend policy without changing
the traversal mechanism.

```{eval-rst}
.. automodule:: myform.degrade
   :members:
   :imported-members:
```