[chillwur]

Problem

Lint, format, and typecheck issues currently aren't caught until CI runs on a pushed branch. That feedback loop is slow — a contributor can push several commits before finding out a file wasn't formatted or has an ESLint error, when the fix would have taken seconds if caught locally at commit time.

Solution

• Added husky and lint-staged as root dev dependencies, with a prepare: husky script so hooks are installed automatically on pnpm install.
• Added a .husky/pre-commit hook that runs pnpm exec lint-staged.
• Configured lint-staged in the root package.json:
  • Staged .ts files under apps/backend run that workspace's ESLint (--fix) then Prettier (--write).
  • Staged .ts/.tsx files under apps/frontend run that workspace's ESLint (--fix) then Prettier (--write).
  • Staged .rs files under contracts/* run cargo fmt --check against the contract's Cargo.toml.
• Only staged files are touched, so the hook stays fast — it does not run the full pnpm build/pnpm test suite.
• Documented the hook and how to bypass it in exceptional cases (git commit --no-verify) in CONTRIBUTING.md, noting CI still runs the full checks regardless.
• Verified the hook end-to-end: staging a deliberately malformed .ts file and running lint-staged correctly reformatted it before commit.

closes #4