switch nextcloud to FPM + Nginx for better static file performance

Replace the all-in-one Apache image with nextcloud:33-fpm and an Nginx
sidecar that serves static assets directly with gzip compression and
cache headers, avoiding the prefork concurrency bottleneck.

nextcloud/docker-compose.yml

@@ -1,6 +1,6 @@
 services:
   nextcloud:
-    image: nextcloud:33-apache
+    image: nextcloud:33-fpm
     container_name: nextcloud
     restart: unless-stopped
     depends_on:
@@ -19,6 +19,29 @@ services:
       - ${DATA_ROOT}/nextcloud/data:/var/www/html/data
       - ./hooks/post-installation.sh:/docker-entrypoint-hooks.d/post-installation/post-installation.sh:ro
       - ./hooks/post-upgrade.sh:/docker-entrypoint-hooks.d/post-upgrade/post-upgrade.sh:ro
+    networks:
+      - nextcloud-internal
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
+
+  nginx:
+    image: nginx:alpine
+    container_name: nextcloud-nginx
+    restart: unless-stopped
+    depends_on:
+      - nextcloud
+    volumes:
+      - ${DATA_ROOT}/nextcloud/html:/var/www/html:ro
+      - ${DATA_ROOT}/nextcloud/data:/var/www/html/data:ro
+      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
+    healthcheck:
+      test: ["CMD-SHELL", "wget -q --spider http://localhost/status.php || exit 1"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
     networks:
       - proxy
       - nextcloud-internal
@@ -27,11 +50,6 @@ services:
       options:
         max-size: "10m"
         max-file: "3"
-    healthcheck:
-      test: ["CMD", "curl", "-f", "http://localhost/status.php"]
-      interval: 30s
-      timeout: 10s
-      retries: 3
 
   postgres:
     image: postgres:17-alpine
@@ -68,7 +86,7 @@ services:
         max-file: "3"
 
   cron:
-    image: nextcloud:33-apache
+    image: nextcloud:33-fpm
     container_name: nextcloud-cron
     restart: unless-stopped
     depends_on: