Migrate from Yarn to pnpm (#201)

* Migrate from Yarn to pnpm

Replace Yarn 3.5.0 (Berry) with pnpm 10.29.3 as the package manager for
both the root project and the example folder.

Changes:
- Update packageManager field in root and example package.json
- Replace yarn commands with pnpm in all scripts
- Add eslint-plugin-prettier as explicit devDependency (required by pnpm's
  strict dependency resolution)
- Add pnpm-compatible transformIgnorePatterns for Jest (handles .pnpm
  directory structure)
- Configure pnpm.onlyBuiltDependencies for pre-commit hook support
- Update GitHub Actions CI to use pnpm/action-setup@v4 with caching
- Remove .yarn directory, .yarnrc.yml, and yarn.lock from both root and
  example
- Add pnpm-lock.yaml
- Update CLAUDE.md to reflect pnpm commands

https://claude.ai/code/session_01SUpZUWxrTYoGms6QN3VtQ9

* Remove pre-commit hook and library

- Remove `pre-commit` devDependency and its `spawn-sync` transitive dep
- Remove `"pre-commit"` config section from package.json
- Remove `lint-and-test` script (was only used by pre-commit)
- Remove `pnpm.onlyBuiltDependencies` config (no longer needed)
- Remove git pre-commit hook file
- Update CLAUDE.md to remove pre-commit references

https://claude.ai/code/session_01SUpZUWxrTYoGms6QN3VtQ9

* Run CI on all branches

Remove branch filters from GitHub Actions workflow so CI runs on
all pushes and pull requests, not just master.

https://claude.ai/code/session_01SUpZUWxrTYoGms6QN3VtQ9

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: gusgard

.github/workflows/node.js.yml

@@ -5,9 +5,7 @@ name: Node.js CI
 
 on:
   push:
-    branches: [ master ]
   pull_request:
-    branches: [ master ]
 
 jobs:
   build:
@@ -20,13 +18,14 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+    - name: Install pnpm
+      uses: pnpm/action-setup@v4
     - name: Use Node.js ${{ matrix.node-version }}
       uses: actions/setup-node@v4
       with:
         node-version: ${{ matrix.node-version }}
-    - name: Enable Corepack
-      run: corepack enable
-    - run: yarn install
-    - run: yarn tsc
-    - run: yarn lint
-    - run: yarn jest
+        cache: 'pnpm'
+    - run: pnpm install
+    - run: pnpm tsc
+    - run: pnpm lint
+    - run: pnpm jest

.gitignore

@@ -35,6 +35,7 @@ local.properties
 node_modules/
 npm-debug.log
 yarn-error.log
+pnpm-debug.log
 
 # BUCK
 buck-out/