genControl .lt crashes when controller literal is 0

## Description

`genControl` crashes when the `.lt` operator is used with a controller literal of 0, because `choose` receives an invalid range.

## Location

`src/Codec/CBOR/Cuddle/CBOR/Gen.hs`, `genControl` function

## Details

```haskell
(CtlOp.Lt, CTree.Literal (Value (VUInt n) _)) -> case target of
CTree.Postlude PTUInt -> S . TInteger <$> choose (0, fromIntegral n - 1)
```

When `n == 0`, `choose (0, fromIntegral n - 1)` becomes `choose (0, -1)`, which is an invalid range.

## Suggested fix

Handle `n == 0` explicitly with a clear error message about the empty range (there are no unsigned integers less than 0).