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>

dashboard/src/server/env.ts

@@ -0,0 +1,35 @@
+import path from "node:path";
+
+/**
+ * Central environment access. In production these are set by docker-compose;
+ * in local dev sensible fallbacks point at ./dev-data so the app boots
+ * without the container stack (integrations degrade to "offline" states).
+ */
+const dev = process.env.NODE_ENV !== "production";
+
+function str(key: string, fallback: string): string {
+  const v = process.env[key];
+  return v !== undefined && v !== "" ? v : fallback;
+}
+
+export const env = {
+  dev,
+  sessionSecret: str("PANEL_SESSION_SECRET", dev ? "craftdeck-dev-secret-do-not-use" : ""),
+  initialAdminPassword: str("PANEL_ADMIN_PASSWORD", dev ? "admin" : ""),
+
+  rconHost: str("RCON_HOST", "127.0.0.1"),
+  rconPort: Number(str("RCON_PORT", "25575")),
+  rconPassword: str("RCON_PASSWORD", "minecraft"),
+
+  dockerSocket: str("DOCKER_SOCKET", "/var/run/docker.sock"),
+  mcContainer: str("MC_CONTAINER", "mc"),
+  backupContainer: str("BACKUP_CONTAINER", "mc-backup"),
+
+  mcDataDir: path.resolve(str("MC_DATA_DIR", dev ? "./dev-data/mc" : "/mc-data")),
+  backupsDir: path.resolve(str("BACKUPS_DIR", dev ? "./dev-data/backups" : "/backups")),
+  appDataDir: path.resolve(str("APP_DATA_DIR", dev ? "./dev-data/app" : "/app-data")),
+  projectDir: path.resolve(str("PROJECT_DIR", dev ? ".." : "/project")),
+
+  registrationWindowMinutes: Number(str("REGISTRATION_WINDOW_MINUTES", "2")),
+  discordWebhookUrl: str("DISCORD_WEBHOOK_URL", ""),
+};