fix: use full nginx.conf instead of conf.d snippet to avoid directive nesting error

Alpine nginx includes conf.d/*.conf inside the http{} block, but our
template contained map/log_format directives and a server{} block that
conflicted with the include structure. Switched to a complete standalone
nginx.conf with proper user/events/http nesting.

docker-entrypoint.sh

@@ -5,8 +5,9 @@ set -e
 # Ensure nginx can write to the shared logs directory
 mkdir -p /logs && chown nginx:nginx /logs
 
-# Render nginx config from template
-sed "s|__API_UPSTREAM__|${API_UPSTREAM}|g" /etc/nginx/conf.d/nginx.conf.template > /etc/nginx/conf.d/default.conf
+# Render nginx config from template to /etc/nginx/nginx.conf
+# (full config, not conf.d/ snippet — avoids Alpine include nesting issues)
+sed "s|__API_UPSTREAM__|${API_UPSTREAM}|g" /etc/nginx/conf.d/nginx.conf.template > /etc/nginx/nginx.conf
 
 # Render client-side config.json for fallback use
 envsubst '${API_PUBLIC_URL}' < /usr/share/nginx/html/config.json.template > /usr/share/nginx/html/config.json