feat(deploy): add compose deployment

deploy/compose.env.example

@@ -0,0 +1,38 @@
+# Copy this file to .env before running Docker Compose:
+#   cp deploy/compose.env.example .env
+
+# Public web port exposed by the web service.
+CHECKIN_WEB_PORT=8080
+
+# ==================== Backend runtime paths ====================
+# Container-local defaults for the Compose deployment.
+DATABASE_URL=sqlite:////app/data/checkin.db
+LOG_FILE=/app/logs/backend.log
+SESSION_DIR=/app/sessions
+
+# ==================== Security and public URLs ====================
+# Change this before production use.
+SECRET_KEY=change-this-to-a-long-random-secret
+
+# Use the browser origins that will open the frontend.
+# Public domain + optional intranet origins.
+CORS_ORIGINS=https://checkin.example.com,http://192.168.1.10:8080,http://checkin.lan:8080
+FRONTEND_URL=https://checkin.example.com
+
+# ==================== Logging ====================
+LOG_LEVEL=INFO
+
+# ==================== Mail settings ====================
+SMTP_SERVER=smtp.example.com
+SMTP_PORT=465
+SMTP_SENDER_EMAIL=your-email@example.com
+SMTP_SENDER_PASSWORD=your-auth-code-here
+SMTP_USE_SSL=True
+
+# ==================== Playwright browser settings ====================
+# Leave empty to use the Chromium installed in the backend image.
+BROWSER_EXECUTABLE_PATH=
+
+# ==================== Scheduler settings ====================
+TOKEN_CHECK_INTERVAL_MINUTES=30
+SESSION_CLEANUP_INTERVAL_HOURS=24