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>

docs/updating.md

@@ -0,0 +1,39 @@
+# Updating
+
+## Upgrading Minecraft (e.g. 26.2 → 26.3)
+
+1. **Configuration** page → change `Minecraft version` → **Save**
+2. **Apply** with *"Take a safety backup first"* enabled
+3. The server container is recreated: the new server jar, a matching Fabric loader, and
+   fresh builds of every managed mod are downloaded automatically
+
+If a managed mod has no build for the new version yet, the server won't start — check
+the Console page for which one, remove it from the Mods page (or wait a few days), and
+Apply again. Worlds upgrade forward automatically; **there is no downgrade** — that's
+what the safety backup is for.
+
+Command-line equivalent:
+
+```bash
+sed -i 's/^MC_VERSION=.*/MC_VERSION=26.3/' .env
+docker exec mc-backup backup now
+docker compose up -d mc
+```
+
+## Updating mods only
+
+Mods page → **Update all & restart**. (Any server restart re-resolves managed mods.)
+
+## Updating the panel / images
+
+```bash
+git pull
+docker compose pull          # new itzg server + backup images
+docker compose build dashboard
+docker compose up -d
+```
+
+## Snapshots / release candidates
+
+`MC_VERSION` accepts any version the launcher knows (`26.3-rc-1`, `26.3-snapshot-3`…).
+Mods rarely support snapshots — expect to trim the mod list if you try them.