chore(docker): add healthcheck to full docker-compose gateway service

Add Docker healthcheck configuration to the picoclaw-gateway service
in docker-compose.full.yml for consistency with the standard compose file.

This ensures the full MCP support variant also has proper health monitoring.

docker/docker-compose.full.yml

@@ -38,6 +38,12 @@ services:
       # NPM cache for faster MCP server installs
       - picoclaw-npm-cache:/root/.npm
     command: ["gateway"]
+    healthcheck:
+      test: ["CMD", "wget", "-q", "--spider", "http://localhost:18790/health"]
+      interval: 30s
+      timeout: 3s
+      start_period: 5s
+      retries: 3
 
 volumes:
   picoclaw-workspace: