Phaser event types should be literal types instead of `string`

Version

• Phaser Version: v3.90.0
• Operating system: Ubuntu 24.04 LTS (irrelevant)

Description

The published .d.ts files for Phaser do not include the string names of various event constants.
This means external consumers using Phaser in a TypeScript project will see the types of PhaserCore..Events.BOOT as string, not the actual "boot" value that it assumes at runtime, making strongly typing event-related code effectively impossible.

Example Test Code

import Phaser from "phaser";

type bootEvt = typeof Phaser.Core.Events.BOOT;
//  ^  string, not "boot"

Additional Information

This can be easily fixed by changing the @type {string}s inside the module code to the actual value of their respective constants.

I might make a PR for this if I find the time; it is fairly easy and quick to fix (as well as something an end user cannot fix simply by overriding Phaser's typings)

Start with the event module code, including src/core/events/BLUR_EVENT.js, and inspect the @type {string} declarations for the constants mentioned in the issue. Update the declarations so the published .d.ts types preserve each constant's literal runtime value, then verify that typeof Phaser.Core.Events.BOOT is "boot" in a TypeScript project.