Add Caddy landing page with dark LAN service map

Newbie-friendly index of media, download, AI, and git services with
short how-to blurbs; served on port 80 for other PCs on the network.

docker-compose.yml

@@ -8,6 +8,7 @@ name: arr-stack
 #   sabnzbd      Usenet NZB download client (Newshosting, Tweaknews, …)
 #   sonarr       TV         radarr    movies       bazarr    subtitles
 #   jellyfin     media server
+#   landing      Caddy — dark LAN homepage (port 80)
 #
 # AI / coding stack (local, no VPN)
 #   bonsai       Prism Ternary-Bonsai-27B via llama-server (OpenAI-compatible API)
@@ -186,6 +187,19 @@ services:
     # devices:
     #   - /dev/dri:/dev/dri
 
+  # ----------------------------------------------------- LAN landing (Caddy) #
+  # Dark-mode map of services for other PCs on the network: http://server/
+  landing:
+    image: caddy:2-alpine
+    container_name: landing
+    restart: unless-stopped
+    networks: [arr-net]
+    ports:
+      - "${LANDING_PORT:-80}:80"
+    volumes:
+      - ./landing/Caddyfile:/etc/caddy/Caddyfile:ro
+      - ./landing/site:/srv:ro
+
   # ------------------------------------------------------------------- music #
   lidarr:
     image: lscr.io/linuxserver/lidarr:latest