reuseport is legal only once per addr:port (443/udp). preprod and prod
share the same IP today, so enabling it on preprod-Org clashed with
prod-Org and made nginx refuse the config. QUIC_OPTS now resolves to
" reuseport" only when APP_INSTALL_ENV=production AND the host is Org;
preprod and the Api/Blogs vhosts get a plain `listen 443 quic;`.
Also drop the stray space before `;` when QUIC_OPTS is empty by moving
the separator into the QUIC_OPTS value (`listen 443 quic$QUIC_OPTS;`).
Co-Authored-By: Claude Code <noreply@anthropic.com>