refactor: modernization project foundation

[yangxu52]

This PR establishes the first modernization baseline for the repository and development workflow.

It focuses on package management, formatting, static checks, CI, pre-commit automation, and clearer TypeScript
configuration boundaries.

There are no intentional public runtime API changes in this PR.

Included commits

1. chore: adopt pnpm for repository development

   • switch development workflow from npm to pnpm
   • require Node.js >=18.12.0 and pnpm >=10 via engines
   • remove package-lock.json and keep pnpm-lock.yaml
   • update build and debug docs to use pnpm
   • fix webpack ts-loader exclude node_modules typo

2. chore: add formatting baseline

   • ignore .local task artifacts and pnpm debug logs
   • add editorconfig and gitattributes for basic repo formatting rules
   • add prettier config and ignore rules
   • add prettier as a dev dependency

3. chore: add lint and typecheck baseline

   • add ESLint 9 flat config
   • add lint, tsc, and check scripts
   • align tsconfig with noEmit checks
   • add @types to fix index.js TS9006 issue

4. ci: add GitHub Actions check workflow

   • run pnpm check on push and pull_request

5. chore: add husky pre-commit checks

   • initialize husky through the prepare script
   • run lint-staged from the pre-commit hook
   • apply eslint --fix and prettier --write to staged files

6. chore: split tsconfig for check and build

   • use tsconfig.json as the noEmit typecheck entry
   • add tsconfig.build.json for webpack bundling
   • bind ts-loader to the build config explicitly

Validated with:

• pnpm check
• `pnpm build