feat(standalone): 新增单机模式，KILOSTAR_MODE=standalone 时去掉 Ray 依赖

通过 StandaloneProxy 适配层让 .remote() 调用在单机模式下透明降级为
asyncio 协程调用，7 个 Actor 和 workflow task 均可在纯 asyncio 环境运行，
启动快、资源占用低。分布式模式行为完全不变。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

kilostar/worker_cluster/worker_cluster.py

@@ -12,12 +12,18 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-import ray
+import os
 import time
 import asyncio
 from collections import OrderedDict
-from ray.util.queue import Queue
+from kilostar.utils.standalone_proxy import actor_class
 from kilostar.utils.ray_hook import ray_actor_hook
+
+_STANDALONE = os.environ.get("KILOSTAR_MODE", "distributed") == "standalone"
+if _STANDALONE:
+    from asyncio import Queue
+else:
+    from ray.util.queue import Queue
 from kilostar.worker_individual.base_individual import BaseIndividual
 from kilostar.worker_individual.skill_individual import SkillIndividual
 from kilostar.worker_individual.ordinary_individual import OrdinaryIndividual
@@ -27,7 +33,7 @@ from kilostar.worker_individual.special_individual import SpecialIndividual
 from kilostar.utils.logger import get_logger
 
 
-@ray.remote
+@actor_class
 class WorkerCluster:
     """
     工作集群 Actor：管理和调度所有的 worker_individual