feat(compose): optional static/mirror via override files; build-stack up modes

Base compose is core only (dnsmasq, drasl, minecraft, mc-backup, caddy
auth+packwiz). docker-compose.static.yml and docker-compose.mirror.yml layer
on the landing site and the air-gap mirror independently. build-stack.sh --up
[core|static|mirror|full] selects the override files.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker-compose.static.yml

@@ -0,0 +1,10 @@
+# Static toggle — apex landing page + launcher downloads.
+# Layer on top of the base: `docker compose -f docker-compose.yml -f docker-compose.static.yml up -d`
+# (or `tooling/build-stack.sh --up static`). Adds the static vhost snippet plus
+# the www + launcher content mounts. Build www first: cd landing && pnpm run build.
+services:
+  caddy:
+    volumes:
+      - ./caddy/conf.d/10-static.caddy:/etc/caddy/conf.d/10-static.caddy:ro
+      - ./www:/srv/www:ro
+      - ./mirror/launcher:/srv/launcher:ro