drpc-free: default GW_FREE_REDIS_RAM to 512MB (empty var made redis-free crash-loop on us-45)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

drpc-free.yml

@@ -30,7 +30,7 @@ services:
     restart: unless-stopped
     command:
       - "redis-server"
-      - "--maxmemory ${GW_FREE_REDIS_RAM}"
+      - "--maxmemory ${GW_FREE_REDIS_RAM:-512MB}"
       - "--maxmemory-policy allkeys-lru"
       - '--save ""'
     networks: