feat: 人设模板系统、节点调度标签、pydantic-settings收敛、错误处理增强

新增persona_template表和CRUD API，BaseIndividualModel增加node_affinity和template_origin_id字段，
WorkerCluster支持多集群Ray资源调度，环境变量收敛到pydantic-settings统一校验，
数据库异常转换为结构化BusinessError/RetryableError，系统节点支持custom_system_prompt。

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

kilostar/utils/logger.py

@@ -12,7 +12,6 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-import os
 import sys
 
 from loguru import logger
@@ -23,15 +22,11 @@ from kilostar.utils.request_context import get_request_id, get_trace_id
 
 
 def _is_json_mode() -> bool:
-    """根据环境变量决定是否启用 JSON 结构化日志。
-
-    支持开关：``KILOSTAR_LOG_FORMAT=json`` 或 ``KILOSTAR_LOG_JSON=1/true``。
-    """
-    fmt = os.environ.get("KILOSTAR_LOG_FORMAT", "").lower()
-    if fmt == "json":
+    from kilostar.utils.settings import get_settings
+    s = get_settings().log
+    if s.kilostar_log_format.lower() == "json":
         return True
-    flag = os.environ.get("KILOSTAR_LOG_JSON", "").lower()
-    return flag in {"1", "true", "yes", "on"}
+    return s.kilostar_log_json.lower() in {"1", "true", "yes", "on"}
 
 
 def _ctx_patcher(record):
@@ -58,7 +53,8 @@ def setup_logger() -> Logger:
     """
     logger.remove()
 
-    log_level = os.environ.get("KILOSTAR_LOG_LEVEL", "DEBUG").upper()
+    from kilostar.utils.settings import get_settings
+    log_level = get_settings().log.kilostar_log_level.upper()
 
     if _is_json_mode():
         logger.configure(