feat: implement async DeploymentExecutor pipeline

- Async container deployment with health check polling
- Stops previous deployment before starting new one
- Configurable memory, CPU, health timeout via application properties
- @EnableAsync on application class for Spring async proxy

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cameleer3-server-app/src/main/java/com/cameleer3/server/app/Cameleer3ServerApplication.java

@@ -5,6 +5,7 @@ import com.cameleer3.server.app.config.IngestionConfig;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.scheduling.annotation.EnableAsync;
 import org.springframework.scheduling.annotation.EnableScheduling;
 
 /**
@@ -16,6 +17,7 @@ import org.springframework.scheduling.annotation.EnableScheduling;
         "com.cameleer3.server.app",
         "com.cameleer3.server.core"
 })
+@EnableAsync
 @EnableScheduling
 @EnableConfigurationProperties({IngestionConfig.class, AgentRegistryConfig.class})
 public class Cameleer3ServerApplication {