vite.config.ts hardcoded the /api, /admin, /healthz proxy targets to
http://localhost:3000 — the server's default port — so there was no
way to run dev:client against a dev:server started on a different
port (PORT=<n> pnpm dev:server) without editing the config file.
Read the port from WUTZ_SERVER_PORT (same default of 3000 as the
server's own PORT env var) and build the proxy target once.
a5698c62bc