Minecraft 26.2 Fabric server stack with CraftDeck management panel

- docker-compose: itzg/minecraft-server (Fabric, offline mode, whitelist
  enforced, Modrinth-managed mods), itzg/mc-backup sidecar, custom dashboard
- Gated auth for offline mode: approve username -> whitelisted with a short
  registration window -> EasyAuth /register + /login; auto-revoke on expiry
- CraftDeck panel (Next.js 16, zero native deps): live console (SSE), players
  & stats, lag diagnostics (server TPS vs player ping via spark), performance
  graphs, Modrinth mod search/manager, backups & restore, sandboxed file
  browser/editor, .env config editor with compose apply, cron schedules,
  Discord alerts, scrypt-hashed panel login
- scripts/setup.sh generates secrets; docs/ covers auth, mods, updating,
  backups, networking (Tailscale), troubleshooting

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,53 @@
+# ──────────────────────────────────────────────────────────────────────────
+# Minecraft server + dashboard configuration
+# Copy to .env (scripts/setup.sh does this and generates the secrets).
+# After changing values, apply with:  docker compose up -d
+# ──────────────────────────────────────────────────────────────────────────
+
+# ── Minecraft ────────────────────────────────────────────────────────────
+# Game version. Change and re-run `docker compose up -d mc` to upgrade.
+MC_VERSION=26.2
+# Loader: FABRIC (default), NEOFORGE, FORGE, VANILLA, PAPER, ...
+SERVER_TYPE=FABRIC
+# JVM heap for the server. Host has 10 GB → 6G heap / 7g container limit.
+MC_MEMORY=6G
+MC_CONTAINER_MEM_LIMIT=7g
+MC_PORT=25565
+
+MC_MOTD=A cozy server for friends
+MC_DIFFICULTY=normal
+MC_MAX_PLAYERS=10
+MC_VIEW_DISTANCE=10
+MC_SIMULATION_DISTANCE=8
+# Leave empty for a random world seed
+MC_SEED=
+
+# Server-side mods (Modrinth project slugs, comma-separated).
+# Auto-resolved to the newest compatible release on every container start.
+MODRINTH_PROJECTS=fabric-api,easyauth,spark,lithium,ferrite-core
+# To run a full modpack instead, set its Modrinth slug (e.g. adrenaline)
+# and see docs/mods-and-modpacks.md before enabling.
+MODRINTH_MODPACK=
+
+# ── Secrets (generated by scripts/setup.sh — never commit .env) ──────────
+RCON_PASSWORD=CHANGE_ME
+PANEL_SESSION_SECRET=CHANGE_ME
+# Initial dashboard admin password. Used only to seed the first login;
+# you are forced to change it in the UI afterwards.
+PANEL_ADMIN_PASSWORD=CHANGE_ME
+
+# ── Dashboard ────────────────────────────────────────────────────────────
+DASHBOARD_PORT=8080
+# Minutes an approved player has to /register before approval expires
+REGISTRATION_WINDOW_MINUTES=2
+# Optional: Discord webhook for alerts (joins, downtime, backups, lag)
+DISCORD_WEBHOOK_URL=
+
+# ── Backups ──────────────────────────────────────────────────────────────
+# Interval between automatic backups (e.g. 6h, 24h)
+BACKUP_INTERVAL=24h
+# Delete backups older than this many days
+BACKUP_RETENTION_DAYS=7
+
+# ── Misc ─────────────────────────────────────────────────────────────────
+TZ=UTC