Initial commit: self-hosted Docker setup for OpenFrontIO

Includes docker-compose, setup script, nginx reverse proxy docs,
and GAME_ENV configuration notes for self-hosted deployments.

.env.example

@@ -0,0 +1,35 @@
+# ============================================================
+# OpenFrontIO — Docker Compose Environment Configuration
+# Copy this file to .env and adjust values as needed.
+# ============================================================
+
+# Port to expose the game on the host machine (default: 80)
+HOST_PORT=8989
+
+# Git commit hash embedded in the build for version tracking.
+# Automatically set by setup.sh. Can also be pinned to a specific commit.
+GIT_COMMIT=unknown
+
+# Game environment: dev | staging | prod
+# Must be set, otherwise /api/env returns HTTP 500 and the frontend breaks.
+# Use "dev" for self-hosted setups — prod/staging use domain-bound Cloudflare
+# Turnstile keys (openfront.io / openfront.dev) that fail on other domains (error 110200).
+GAME_ENV=dev
+
+# ============================================================
+# Cloudflare Tunnel (optional)
+# Leave all CF_* variables empty to run without a tunnel.
+# The server will then be accessible only via HOST_PORT.
+# ============================================================
+
+# Cloudflare API token with Tunnel:Edit and DNS:Edit permissions
+CF_API_TOKEN=
+
+# Cloudflare Account ID (from the Cloudflare dashboard URL)
+CF_ACCOUNT_ID=
+
+# Subdomain prefix for the tunnel (e.g. "myserver" → tunnel-myserver.example.com)
+SUBDOMAIN=
+
+# Root domain managed by Cloudflare (e.g. "example.com")
+DOMAIN=openfront.muc.datenh.eu