fix(ci): Pass PLAYWRIGHT_BROWSERS_PATH through sudo

sudo resets environment variables by default, so the ENV set in the
Dockerfile wasn't visible to the npx playwright install command.
Explicitly pass the variable so browsers are installed to /opt/pw-browsers.

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

Author: mydea

.github/docker/playwright.Dockerfile

@@ -24,7 +24,7 @@ RUN sudo curl -fsSL https://deb.nodesource.com/setup_${NODE_VERSION%%.*}.x | sud
 # (GHA sets HOME=/github/home inside containers, not /home/runner).
 ENV PLAYWRIGHT_BROWSERS_PATH=/opt/pw-browsers
 RUN sudo mkdir -p /opt/pw-browsers && \
-    sudo npx playwright@${PLAYWRIGHT_VERSION} install chromium webkit firefox --with-deps
+    sudo PLAYWRIGHT_BROWSERS_PATH=/opt/pw-browsers npx playwright@${PLAYWRIGHT_VERSION} install chromium webkit firefox --with-deps
 
 # Mark GitHub Actions workspace as safe for git (system-wide config so it
 # works regardless of HOME, which GHA overrides to /github/home).