ci: Skip Playwright install for e2e apps without @playwright/test

Move the "does this app need Playwright" decision into the install-playwright
action: it resolves @playwright/test from the app and, when the package isn't
there, emits an empty version and skips the browser install (and its cache
steps) instead of failing on the missing require. Apps that assert via a plain
node script (e.g. the node bundler apps) no longer pay for a Playwright install
they don't use, with no per-app config or extra workflow step to maintain.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: mydea

.github/actions/install-playwright/action.yml

@@ -11,15 +11,21 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    # Resolve the app's @playwright/test version. Some apps (e.g. the node bundler apps) assert via a
+    # plain node script and don't depend on Playwright — emit an empty version instead of failing, so
+    # the steps below skip the (wasted) browser install rather than erroring on the missing package.
     - name: Get Playwright version
       id: playwright-version
-      run: echo "version=$(node -p "require('@playwright/test/package.json').version")" >> $GITHUB_OUTPUT
+      run: |
+        version=$(node -e "let v = ''; try { v = require('@playwright/test/package.json').version; } catch {} process.stdout.write(String(v));")
+        echo "version=$version" >> "$GITHUB_OUTPUT"
       shell: bash
       working-directory: ${{ inputs.cwd }}
 
     - name: Restore cached playwright binaries
       uses: actions/cache/restore@v6.1.0
       id: playwright-cache
+      if: steps.playwright-version.outputs.version != ''
       with:
         path: |
           ~/.cache/ms-playwright
@@ -29,22 +35,24 @@ runs:
     # We always install all browsers, if uncached
     - name: Install Playwright dependencies (uncached)
       run: npx playwright install chromium webkit firefox --with-deps
-      if: steps.playwright-cache.outputs.cache-hit != 'true'
+      if: steps.playwright-version.outputs.version != '' && steps.playwright-cache.outputs.cache-hit != 'true'
       shell: bash
       working-directory: ${{ inputs.cwd }}
 
     - name: Install Playwright system dependencies only (cached)
       env:
         PLAYWRIGHT_BROWSERS: ${{ inputs.browsers || 'chromium webkit firefox' }}
       run: npx playwright install-deps "$PLAYWRIGHT_BROWSERS"
-      if: steps.playwright-cache.outputs.cache-hit == 'true'
+      if: steps.playwright-version.outputs.version != '' && steps.playwright-cache.outputs.cache-hit == 'true'
       shell: bash
       working-directory: ${{ inputs.cwd }}
 
     # Only store cache on develop branch
     - name: Store cached playwright binaries
       uses: actions/cache/save@v6.1.0
-      if: github.event_name == 'push' && github.ref == 'refs/heads/develop'
+      if:
+        steps.playwright-version.outputs.version != '' && github.event_name == 'push' && github.ref ==
+        'refs/heads/develop'
       with:
         path: |
           ~/.cache/ms-playwright