Migrate to @playcanvas/eslint-config v3 (/typescript + /react)

[kpal81xd]

Part of the rollout in playcanvas/eslint-config#48.

What changed

Subpath migration (typescript + react). v3 ships tiered subpath exports instead of a single default config. This is a React app, so it now composes both tiers — /react is additive (JSX / a11y / hooks rules only) and is spread on top of /typescript:

import typescriptConfig from '@playcanvas/eslint-config/typescript';
import reactConfig from '@playcanvas/eslint-config/react';
export default [...typescriptConfig, ...reactConfig, ...overrides];

• Dropped the redundant manual @typescript-eslint plugin/parser wiring and tsPlugin.configs.recommended.rules spread — /typescript provides typescript-eslint recommended + strict + stylistic.
• Dropped the manual import/resolver settings block — /typescript wires the resolver internally via import-x/resolver-next.
• Removed now-defunct jsdoc/* overrides (jsdoc is no longer part of the /typescript tier).
• import → import-x namespace: renamed import/no-unresolved → import-x/no-unresolved (v3's /typescript uses eslint-plugin-import-x). No eslint-disable import/* comments existed in source.
• Kept genuine repo overrides: @typescript-eslint/{ban-ts-comment,no-explicit-any,no-unused-vars}: 'off', browser globals for .ts/.tsx, node globals + import-x/no-unresolved: 'off' for .js/.mjs.
• Added a small but necessary override: /typescript only wires the TS parser for **/*.{js,mjs,ts}, so .tsx files get parser: tseslint.parser explicitly (this app has many .tsx files).

Version bump. @playcanvas/eslint-config 2.1.0 → 3.0.0-beta.5 (carries the import-x resolver fix; verified no import-x/no-unresolved false positives).

devDep cleanup (now bundled transitively by the config, unused elsewhere):

• @typescript-eslint/eslint-plugin
• @typescript-eslint/parser
• eslint-import-resolver-typescript
• globals

Kept eslint, typescript, react/react-dom (runtime), and all build/test deps.

Lint result

lint:fix auto-fixed formatting/order issues across 19 source files. 28 residual errors remain (all genuine findings from v3's stricter ruleset — not config-load errors). Left unfixed per the rollout process:

Count	Rule	Sample
13	@typescript-eslint/prefer-for-of	src/debug-lines.ts:402
3	no-prototype-builtins	src/helpers.ts:32
3	@typescript-eslint/consistent-type-definitions	src/index.tsx:24
3	jsx-a11y/alt-text	src/ui/index.tsx:51
2	import-x/order	src/index.tsx:18
1	@typescript-eslint/no-extraneous-class	src/dummy-webgpu.ts:3
1	no-empty	src/index.tsx:210
1	jsx-a11y/click-events-have-key-events	src/ui/load-controls.tsx:69
1	jsx-a11y/no-static-element-interactions	src/ui/load-controls.tsx:69

Draft until the residual is triaged/fixed in a follow-up.