The Files editor completes and checks TypeScript

TypeScript files in an app's Files editor now get completions as you type: after api. your models and actions, inside a filter a model's fields with their types. Hovering a name shows its type and docs, and type errors are underlined as you type, checked against the SDK and your app's generated types. An error's tooltip offers the fix when it's a misspelling, and Ask the assistant to fix it; a line under the editor lists the file's problems.