Stan 0206 should not fire for type data

I have this code:

```haskell
{-# LANGUAGE TypeData #-}

infixr :->
type data PCFType = PCFType :-> PCFType | Nat
```

And Stan reports:

```
✲ Name: Data types with non-strict fields
✲ Description: Defining lazy fields in data types can lead to unexpected space leaks
✲ Severity: Performance
✲ Category: #SpaceLeak #Syntax
Possible solutions:
- Add '!' before the type, e.g. !Int or !(Maybe Bool)
- Enable the 'StrictData' extension: {-# LANGUAGE StrictData #-}
stan(STAN-0206)
```

But strictness fields are not allowed in `type data` declarations.

Start by reproducing the Haskell snippet with the TypeData extension and confirming the STAN-0206 report. Trace the STAN-0206 implementation and its tests, then ensure type data declarations are excluded from the non-strict-field warning while ordinary data declarations retain the existing behavior.

Written by the indexing model from the issue text.