diff --git a/bioflow_service/app/context.py b/bioflow_service/app/context.py
index cb880a8..4bfc967 100644
--- a/bioflow_service/app/context.py
+++ b/bioflow_service/app/context.py
@@ -165,8 +165,11 @@ async def init_context(db_path: str | None = None) -> Context:
     # 失败(如 docker 不可用/配置缺失)静默降级——trial/run 返回 503 而非 500。
     try:
         from .services.bioflow import extensions as ext_mod
-        from .services.bioflow.extension_exec import ExtensionExecConfig, ExtensionExecutor as RealExecutor
-        cfg = ExtensionExecConfig()
+        # 2026-09-15 修复:裸 ExtensionExecConfig() 的 entry_script_dir 为空串,
+        # build_command 用相对路径 run_extension.py 在 176 cwd 下找不到入口。
+        # 改走 _default_exec_config()(经 _resolve_extension_entry_dir 解析部署树路径)。
+        from .services.bioflow.extension_exec import _default_exec_config, ExtensionExecutor as RealExecutor
+        cfg = _default_exec_config()
         real = RealExecutor(cfg)
         store = ext_mod.get_store()
         if store is not None: