ci: parallelize snapshot updates using matrix strategy

Split the monolithic update-snapshots job into parallel matrix jobs
(3 unit + 3 e2e) that each independently run their snapshot updates,
package changed files as tar artifacts, and a final push job that
collects all results and commits them together. This follows the same
pattern used in the CVE overview pipeline.

https://claude.ai/code/session_01TBWeAQfYF8EFS82Fe4ugkv

Author: claude

.github/workflows/update-snapshots.yml

@@ -15,6 +15,75 @@ concurrency:
 
 jobs:
   update-snapshots:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: components-unit
+            command: pnpm --filter @public-ui/components test:update:unit
+            type: unit
+          - name: hydrate-server-unit
+            command: pnpm --filter @public-ui/hydrate-server test:update:unit
+            type: unit
+          - name: hydrate-unit
+            command: pnpm --filter @public-ui/hydrate test:update:unit
+            type: unit
+          - name: theme-default-e2e
+            command: pnpm --filter @public-ui/theme-default test:update:e2e
+            type: e2e
+          - name: theme-kern-e2e
+            command: pnpm --filter @public-ui/theme-kern test:update:e2e
+            type: e2e
+          - name: test-tag-name-transformer-e2e
+            command: pnpm --filter @public-ui/test-tag-name-transformer test:update:e2e
+            type: e2e
+    steps:
+      - name: Checkout branch
+        uses: actions/checkout@v6
+        with:
+          ref: ${{ github.ref_name }}
+          persist-credentials: false
+
+      - uses: ./.github/actions/pnpm-setup
+
+      - name: Install Playwright browsers
+        if: matrix.type == 'e2e'
+        run: npx playwright install --with-deps firefox
+
+      - name: Build
+        if: matrix.type == 'e2e'
+        run: pnpm --filter @public-ui/sample-react^... build
+
+      - name: Purge existing snapshots
+        if: inputs.delete_snapshots == true
+        run: |
+          if [ "${{ matrix.type }}" = "e2e" ]; then
+            find packages -name '*.png' -path '*/snapshots/*' | grep -v 'node_modules' | xargs --no-run-if-empty rm -f
+          else
+            find packages \( -path '*/node_modules' -prune \) -o -path '*/__snapshots__/*' -type f -print | xargs --no-run-if-empty rm -f
+          fi
+
+      - name: Run snapshot update
+        run: ${{ matrix.command }}
+
+      - name: Package snapshot changes
+        run: |
+          {
+            git diff --name-only --diff-filter=d HEAD
+            git ls-files --others --exclude-standard
+          } | grep -E '(__snapshots__|snapshots)/' | tar cf snapshots.tar -T - 2>/dev/null || tar cf snapshots.tar --files-from /dev/null
+
+      - name: Upload snapshot artifacts
+        uses: actions/upload-artifact@v7
+        with:
+          name: snapshots-${{ matrix.name }}
+          path: snapshots.tar
+          if-no-files-found: ignore
+          retention-days: 1
+
+  push:
+    needs: update-snapshots
     runs-on: ubuntu-latest
     steps:
       - uses: actions/create-github-app-token@v3
@@ -35,52 +104,27 @@ jobs:
           ref: ${{ github.ref_name }}
           token: ${{ steps.app-token.outputs.token }}
 
-      # https://github.com/pnpm/action-setup#use-cache-to-reduce-installation-time
-      - name: Install Node.js
-        uses: actions/setup-node@v6
-        with:
-          node-version: 22
-
-      - name: Install pnpm
-        uses: pnpm/action-setup@v4
-        id: pnpm-install
-        with:
-          version: 10
-          run_install: false
-
-      - name: Get pnpm store directory
-        id: pnpm-cache
-        shell: bash
-        run: echo "STORE_PATH=$(pnpm store path)" >> $GITHUB_OUTPUT
-
-      - name: Setup pnpm cache
-        uses: actions/cache@v5
-        with:
-          path: ${{ steps.pnpm-cache.outputs.STORE_PATH }}
-          key: ${{ runner.os }}-pnpm-store
-          restore-keys: |
-            ${{ runner.os }}-pnpm-store
-
-      - name: Install
-        run: pnpm i --no-frozen-lockfile
-
-      - name: Install Playwright browsers
-        run: npx playwright install --with-deps firefox
-
-      - name: Build
-        run: pnpm --filter @public-ui/sample-react^... build
-
-      - name: Purge existing snapshots (optional)
+      - name: Purge existing snapshots
         if: inputs.delete_snapshots == true
-        run: find packages -name '*.png' -path '*/snapshots/*' | grep -v 'node_modules' | xargs rm # Remove any existing snapshots, except those in node_modules
+        run: |
+          find packages -name '*.png' -path '*/snapshots/*' | grep -v 'node_modules' | xargs --no-run-if-empty rm -f
+          find packages \( -path '*/node_modules' -prune \) -o -path '*/__snapshots__/*' -type f -print | xargs --no-run-if-empty rm -f
 
-      - name: Display git status (before test-update)
-        run: git status
-
-      - name: Run snapshot updates
-        run: pnpm test:update
-
-      - name: Display git status (after test-update)
+      - name: Download snapshot artifacts
+        uses: actions/download-artifact@v8
+        with:
+          pattern: snapshots-*
+          path: snapshot-artifacts
+
+      - name: Apply snapshot updates
+        run: |
+          for dir in snapshot-artifacts/snapshots-*/; do
+            if [ -f "${dir}snapshots.tar" ]; then
+              tar xf "${dir}snapshots.tar"
+            fi
+          done
+
+      - name: Display git status
         run: git status
 
       - name: Stage snapshot changes