feat: add setup script and migrate CI to pnpm

- Created `setup.sh` to automate environment setup.
- Added Playwright for visual testing and Prettier for formatting.
- Updated `.github/workflows/deploy.yml` to use `pnpm` and fixed lockfile mismatch.
- Synchronized `package-lock.json` and `pnpm-lock.yaml`.
- Updated `.gitignore` to exclude test artifacts.

Co-authored-by: rockoder <2136164+rockoder@users.noreply.github.com>

Author: google-labs-jules[bot]

.github/workflows/deploy.yml

@@ -36,20 +36,36 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: "20"
-          cache: npm
-          cache-dependency-path: ${{ env.BUILD_PATH }}/package-lock.json
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+
+      - name: Get pnpm store directory
+        shell: bash
+        run: |
+          echo "STORE_PATH=$(pnpm store path --silent)" >> $GITHUB_ENV
+
+      - name: Setup pnpm cache
+        uses: actions/cache@v4
+        with:
+          path: ${{ env.STORE_PATH }}
+          key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
+          restore-keys: |
+            ${{ runner.os }}-pnpm-store-
 
       - name: Setup Pages
         id: pages
         uses: actions/configure-pages@v5
 
       - name: Install dependencies
-        run: npm ci
+        run: pnpm install --frozen-lockfile
         working-directory: ${{ env.BUILD_PATH }}
 
       - name: Build with Astro
         run: |
-          npm run build
+          pnpm build
         working-directory: ${{ env.BUILD_PATH }}
 
       - name: Upload artifact