## Why

JavaScript, TypeScript, and TSX class declarations were captured as
`type.class`, but the same class names in `new` expressions were
captured as the generic `type`. Themes that define a distinct style for
`type.class` therefore rendered declarations and instantiations
inconsistently.

## What

Update the three highlight queries so constructor identifiers in `new`
expressions use `type.class`. Themes without a dedicated `type.class`
style continue to fall back to their existing `type` style.

Add a regression test that loads the real JavaScript, TypeScript, and
TSX grammars with distinct colors for `type` and `type.class`, then
verifies that both the declaration and instantiation receive the
class-specific highlight.

## Testing

- `cargo test -p languages test_class_instantiation_highlighting`
- `cargo test -p languages`
- `cargo fmt --all -- --check`
- `./script/clippy -p languages`

## References

Closes #55943

Release Notes:

- Fixed inconsistent class instantiation highlighting in JavaScript,
TypeScript, and TSX.