chore: migrate to ESLint config v3

[kpal81xd]

Part of playcanvas/eslint-config#48.

Scope

• Migrated the monorepo to @playcanvas/eslint-config@3.0.0-beta.8 using /typescript followed by /react.
• Reused shared defaults while preserving the React Compiler rule, browser globals, generated self-import resolution, package import-extension policy, and narrowly scoped behavior-sensitive exceptions.
• Added the shared Prettier config, fmt, fmt:fix, and lint:fix scripts, the Prettier dependency, and a CI formatting check.
• Removed direct ESLint dependencies supplied by the shared config and retained eslint-plugin-import because both package configs still use it.
• Applied the shared formatting and fixed all lint errors without runtime or public API changes.

Verification

• corepack pnpm install --frozen-lockfile — passed.
• corepack pnpm exec prettier --check packages eslint.config.mjs prettier.config.mjs — passed.
• corepack pnpm -r exec eslint . — passed with 0 errors and 35 behavior-sensitive hook/compiler warnings.
• corepack pnpm --filter @playcanvas/react run test -- --reporter=dot — 140 passed, 16 skipped.
• corepack pnpm --filter @playcanvas/react run build — passed.
• corepack pnpm --filter @playcanvas/blocks run build — passed.
• corepack pnpm --filter docs run build — exited successfully with no matching workspace project.
• npm pack --dry-run --ignore-scripts in packages/lib — passed, 179 files.
• npm pack --dry-run --ignore-scripts in packages/blocks — passed, 117 files.
• git diff --check — passed.
• Runtime audit — 95 non-test modules had zero executable AST differences after normalizing static import order and syntax-only style changes; 110 modules had zero export-surface or side-effect import-sequence changes.
• Declaration audit — 97 generated declaration files had zero public declaration differences after normalizing type-only import organization and style.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@playcanvas/blocks@322

npm i https://pkg.pr.new/@playcanvas/react@322

commit: a571852

[changeset-bot]

⚠️ No Changeset found

Latest commit: a571852

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR