Add static check: warning on several block/mix/attrs/js/etc subpredicates

```js
block('page')(
tag()('body'),
block('content').tag()('article'),
block('footer').tag()('footer')
)
```

P.S. Test needed.

No file, test path, or implementation entry point is named. Start by locating the existing static-check logic and its tests, then reproduce the supplied block/tag example to determine which subpredicates need warnings. Done means the requested warnings are implemented and covered by tests.

Written by the indexing model from the issue text.