docs: add README (stack summary + launch instructions)

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

README.md

@@ -0,0 +1,77 @@
+# Ulicraft Server
+
+Self-hosted modded Minecraft (NeoForge 1.21.1) for a LAN party, designed to run
+**fully offline**. Self-hosted auth/skins (Drasl), a packwiz modpack, a guest
+landing page, and a transparent mirror of Mojang/launcher assets so guest
+laptops need no internet.
+
+## Stack
+
+| Service | Image | Role |
+|---|---|---|
+| `minecraft` | itzg/minecraft-server | NeoForge 1.21.1 server, `:25565` |
+| `drasl` | unmojang/drasl | Yggdrasil auth + skins (password login) |
+| `caddy` | caddy:alpine | ingress: landing page, auth/packwiz proxy, asset mirror |
+| `dnsmasq` | jpillora/dnsmasq | LAN DNS `*.ulicraft.local` + Minecraft SRV |
+| `mc-backup` | itzg/mc-backup | world backups every 6h via RCON |
+
+Everything keys off two vars in `.env`: `BASE_DOMAIN` (default `ulicraft.local`)
+and `HOST_LAN_IP`. Services are subdomains: `auth.`, `packwiz.`, plus the apex
+landing page.
+
+## Prerequisites
+
+Docker + Docker Compose, and for prep: `pnpm`, `packwiz`, `jq`, `curl`,
+`envsubst`, `sha1sum`.
+
+## Setup
+
+```sh
+cp .env.example .env          # set BASE_DOMAIN, HOST_LAN_IP, RCON_PASSWORD
+```
+
+Point guest laptops' DNS at `HOST_LAN_IP` (resolves `*.ulicraft.local`). On the
+Docker host, free port 53 if `systemd-resolved` holds it (dnsmasq binds the LAN
+IP only).
+
+## Launch
+
+```sh
+tooling/build-stack.sh --prep            # ONLINE, run once: render configs, build
+                                         # landing, mirror mods+assets, fetch
+                                         # launcher, pre-bake the server volume
+
+tooling/build-stack.sh --up [mode]       # bring the stack up
+#   core    base only (no static site, no mirror)
+#   static  + apex landing page + launcher downloads
+#   mirror  + full air-gap asset mirror (HTTPS :443)
+#   full    static + mirror (default)
+```
+
+Down: `docker compose -f docker-compose.yml -f docker-compose.static.yml -f docker-compose.mirror.yml down`
+
+## Join (guests)
+
+1. Open `http://ulicraft.local`, download FjordLauncherUnlocked for your OS.
+2. Add an **authlib-injector** account, URL `http://auth.ulicraft.local/authlib-injector`
+   (register/login at `http://auth.ulicraft.local`).
+3. (Air-gap) Trust the Caddy root CA; in Settings → APIs set **Assets Server**
+   to the mirror if not using DNS spoofing.
+4. Import the pack: `http://packwiz.ulicraft.local/pack.toml`.
+5. Connect to **`mc.ulicraft.local`** (no port — SRV record).
+
+## Layout
+
+```
+docker-compose.yml + .static.yml + .mirror.yml   # core + optional layers
+caddy/Caddyfile + conf.d/*.caddy                 # ingress vhost snippets
+drasl/config/config.toml.tmpl                    # auth config (rendered)
+dnsmasq/dnsmasq.conf.tmpl                         # LAN DNS + SRV (rendered)
+pack/                                            # packwiz modpack source
+landing/                                          # Astro site → www/
+tooling/                                          # build-stack + render/mirror/fetch scripts
+mirror/                                           # vendored jars + launcher + asset mirror (gitignored)
+plan/                                             # full design docs (00–12)
+```
+
+See `plan/00-overview.md` for the full design.