Replace hardcoded GIT_REMOTE variable with a function parameter so the
shared deploy library can push to either the production or test remote
from the same script. Rename push_to_server to push_to_remote and update
both deploy_web.sh and deploy_web_test.sh to pass the appropriate remote.
Replace the previous Next.js build + rsync + archive workflow with a
minimal `push_to_server` helper that only does `git push` to the
`server` remote. Build, install, and start are now expected to be
handled by the server's post-receive hook, removing duplicate logic
and shrinking the script from 164 lines to 46. The old `build`,
`deploy`, `archive`, `setup_env`, and `check_local_build_dir`
functions (along with pnpm/rsync/sshpass usage) have been removed.