Run yarn build when starting up frontend container

[kagesenshi]

Problem statement

frontend docker container at the moment set conf iguration (VITE_* etc) during container build time, which means secrets (API keys etc) and configs are stored in the container image, and configuration could not be changed during docker run. This makes the workflow of uploading container image to container registry prior to deployment to not work properly.

This pull request is a suggestion on modifying frontend Dockerfile to run yarn build when container is starting up so that config are applied during container start.

I'm primarily Python+Linux programmer and not quite a frontend person and has low familiarity with yarn build and how it update config files, not sure if this is the right way to do it, but putting this request here for comment.