Serve extension build (#192)

* add extension build to Docker build process

🤖 Generated with [Claude Code](https://claude.ai/code)

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

* Copy extension build to web directory

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: ppsreejith

web/Dockerfile

@@ -47,6 +47,14 @@ RUN yarn set version 4.3.1
 
 RUN yarn install
 
+# Build extension
+WORKDIR /app/extension
+RUN yarn install
+RUN yarn build
+
+# Copy extension build to web public directory
+RUN cp -r /app/extension/build /app/web/public/extension-build
+
 WORKDIR /app/web
 
 RUN yarn install