Remove Lefthook from development dependencies

CLAUDE.md

@@ -46,5 +46,5 @@ The development workflow uses **jiti** to run `src/bin.ts` directly without a co
 
 - **ESLint** uses flat config (`eslint.config.ts`) with `typescript-eslint` strict + stylistic type-checked rules.
 - **Prettier** uses `prettier-plugin-organize-imports` — import order is auto-managed.
-- **Lefthook** runs pre-commit hooks (type-check → format → lint) with `fail_on_changes: always`, so hooks can auto-fix files but will abort the commit if any file changed, requiring a re-stage.
+- **Lefthook** is an external tool (not a dev dependency) that manages Git hooks. It must be installed independently and set up with `lefthook install`. Pre-commit hooks run type-check → format → lint with `fail_on_changes: always`, so hooks can auto-fix files but will abort the commit if any file changed, requiring a re-stage.
 - **Vitest** requires 100% code coverage (lines, functions, branches, statements) enforced via the `coverage` threshold in `vitest.config.ts`.

README.md

@@ -45,6 +45,12 @@ pnpm install
 
 For more information on pnpm, including adding dependencies or running tools, refer to [this documentation](https://pnpm.io/pnpm-cli).
 
+This template also uses [Lefthook](https://lefthook.dev/) to manage Git hooks. Lefthook is an external tool that must be installed independently — refer to [this guide](https://lefthook.dev/installation/) for installation instructions. Once installed, set up the Git hooks with:
+
+```sh
+lefthook install
+```
+
 ### Developing the Library
 
 This template provides two components: the library itself ([`src/lib.ts`](./src/lib.ts)) and an executable entry point ([`src/bin.ts`](./src/bin.ts)). Write code according to your project requirements. If you're new to [TypeScript](https://www.typescriptlang.org/), refer to [this documentation](https://www.typescriptlang.org/docs/) for guidance.

package.json

@@ -36,7 +36,6 @@
     "@vitest/coverage-v8": "^4.0.15",
     "eslint": "^10.3.0",
     "jiti": "^2.7.0",
-    "lefthook": "^2.1.6",
     "prettier": "^3.8.3",
     "prettier-plugin-organize-imports": "^4.3.0",
     "typescript": "^6.0.3",