fix: install Playwright browsers from lockfile-pinned version in CI

bunx playwright install (without lockfile context) resolved the latest
Playwright from npm, downloading chromium v1208 browsers. But the test
runner used @playwright/test@1.57.0 from the lockfile, which expected
chromium_headless_shell-1200. Fix by running bun install first so bunx
resolves the pinned version.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: pRizz

.github/workflows/ci.yml

@@ -341,8 +341,10 @@ jobs:
           restore-keys: ${{ runner.os }}-playwright-
 
       - name: Install Playwright browsers
-        working-directory: packages/opencode/packages/app
-        run: bunx playwright install --with-deps
+        working-directory: packages/opencode
+        run: |
+          bun install --frozen-lockfile --ignore-scripts
+          bunx --bun playwright install --with-deps
         env:
           PLAYWRIGHT_BROWSERS_PATH: ${{ github.workspace }}/.cache/ms-playwright