Add Railway deployment config for 24/7 cloud paper trading

- Dockerfile: add templates copy, ENV PORT, update CMD to live engine
- Create src/live/health.py: threaded HTTP health server (/health, /state)
- Wire health server into src/live/run.py before engine loop
- Dashboard: add unauthenticated /health endpoint, use PORT env var
- Create railway.toml with Dockerfile builder and health check config
- docker-compose.yml: rename service to live-engine, add PORT env vars

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

railway.toml

@@ -0,0 +1,9 @@
+[build]
+builder = "dockerfile"
+dockerfilePath = "Dockerfile"
+
+[deploy]
+healthcheckPath = "/health"
+healthcheckTimeout = 30
+restartPolicyType = "on_failure"
+restartPolicyMaxRetries = 5