[grade=B] Fix DC-064: Bump Docker memory limit from 512m to 1g

512MB was too tight — container OOM-crashed during startup. Bumped to
1GB memory, 2GB swap, 2 CPUs. Production verified healthy on DNS2.

start.sh

@@ -136,7 +136,7 @@ else
 fi
 
 docker run -d --restart unless-stopped --name ${CONTAINER_NAME} \
-  --memory=512m --memory-swap=1g --cpus=1.5 \
+  --memory=1g --memory-swap=2g --cpus=2 \
   --add-host=get.dashcaddy.net:194.233.88.206 \
   --add-host=get2.dashcaddy.net:194.233.88.206 \
   --dns ${DNS_PRIMARY} \