fix: use bun for Chromium verification (node can't find playwright)

The symlinked node_modules from Docker cache aren't resolvable by
raw node — bun has its own module resolution that handles symlinks.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/evals.yml

@@ -113,7 +113,7 @@ jobs:
       # Verify Playwright can launch Chromium (fails fast if sandbox/deps are broken)
       - name: Verify Chromium
         if: matrix.suite.name == 'e2e-browse'
-        run: node -e "const {chromium}=require('playwright');(async()=>{const b=await chromium.launch({args:['--no-sandbox']});console.log('Chromium OK');await b.close();})()"
+        run: bun -e "import {chromium} from 'playwright';const b=await chromium.launch({args:['--no-sandbox']});console.log('Chromium OK');await b.close()"
 
       - name: Run ${{ matrix.suite.name }}
         env: