feat: add sm64coopdx headless dedicated server

Multi-stage Docker build compiles sm64coopdx from source with HEADLESS=1.
Includes patches for GCC 11 float.h and upstream platform.c fallback bug.
Server runs on UDP 7777, supports 16 players, comes with bundled mods.

Also hardcodes OpenFusion SHARD_IP (was using PUBLIC_HOST variable).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker/docker-compose.dev.yml

@@ -90,7 +90,7 @@ services:
       dockerfile: Dockerfile
     restart: unless-stopped
     environment:
-      SHARD_IP: ${PUBLIC_HOST:-192.168.10.234}
+      SHARD_IP: 192.168.10.234
       MOTD: ${OPENFUSION_MOTD:-Bienvenido a Project Afterlife - FusionFall Academy}
     ports:
       - "23000:23000"
@@ -172,6 +172,25 @@ services:
     volumes:
       - afc_bridge_data:/data
 
+  sm64coopdx:
+    build:
+      context: ../servers/sm64coopdx
+      dockerfile: Dockerfile
+    restart: unless-stopped
+    container_name: sm64coopdx
+    environment:
+      SM64_PORT: ${SM64_PORT:-7777}
+      SM64_PLAYERS: ${SM64_PLAYERS:-16}
+    ports:
+      - "7777:7777/udp"
+    volumes:
+      - sm64_save:/server/save
+      - sm64_mods:/server/mods
+    deploy:
+      resources:
+        limits:
+          memory: 2G
+
 volumes:
   postgres_data:
   minio_data:
@@ -179,6 +198,8 @@ volumes:
   minecraft_ftb_data:
   geth_data:
   afc_bridge_data:
+  sm64_save:
+  sm64_mods:
   certbot_etc:
     external: true
     name: docker_certbot_etc