Enum omitted from build for tsdown versions above 0.21.8

[execaman]

Reproduction link or steps

1. clone and install deps

git clone https://github.com/execaman/discolink.git
cd discolink
git checkout v4.7.0
npm ci

2. build and inspect the expected output

npm run build

3. build with tsdown@latest and inspect the new output

npm i tsdown@latest
npm run build

What is expected?

the EventType enum to be defined and exported from the namespace LavaLyrics

What is actually happening?

only the named export remains, the definition itself is gone
hint: the enum is generated for tsdown versions upto 0.21.8

Any additional comments?

No response