Grammar is incorrect

I discovered earlier that if you turn Strict mode on in the Lezer it actually parses the grammar strictly. Without it, it guesses at what you mean if your grammar is incorrect.

If you turn strict mode one

```
export const uiuaLanguage = LRLanguage.define({
name: "uiua",
parser: parser.configure({
strict: true,
props: [
```

This line stops working:

```
😀 ← "happy"
```

Start at the TypeScript language definition and the parser.configure block shown in the issue, then inspect the grammar rule responsible for the `😀 ← "happy"` line. Reproduce the failure with strict mode enabled and determine what grammar change makes that line parse correctly while retaining strict validation.

Written by the indexing model from the issue text.