fix(deployment): correct Redis health check variable syntax for environment variable access

- Changed health check from $$REDIS_PASSWORD to $REDIS_PASSWORD
- Double dollar sign is Docker Compose variable escaping (wrong context)
- Single dollar sign correctly references environment variable exported by entrypoint
- Health check runs in container shell where REDIS_PASSWORD is available
- Fixes 'container application-redis-1 is unhealthy' deployment failure

docker-compose.production.yml

@@ -211,7 +211,7 @@ services:
     # Stricter health checks
     # Uses REDIS_PASSWORD environment variable exported by entrypoint
     healthcheck:
-      test: ["CMD-SHELL", "redis-cli -a \"$$REDIS_PASSWORD\" ping | grep -q PONG"]
+      test: ["CMD-SHELL", "redis-cli -a \"$REDIS_PASSWORD\" ping | grep -q PONG"]
       interval: 10s
       timeout: 3s
       retries: 5