Non library files / code being bundled for core

`@accelint/core`

<img width="1037" height="369" alt="Image" src="https://github.com/user-attachments/assets/9bb5620d-924c-44ef-913f-a3fe260ed1a5" />

We are only excluding `__fixture__` not `__fixtures__` which is why this leaked in there.

```
entry: [
    'src/**/*.{ts,tsx}',
    '!src/**/*.{d,stories,test,test-d,bench}.{ts,tsx}',
    '!**/__fixture__',
  ],
```