fix(ci): restore TaskSpec re-export in task_scheduler.py

ruff --fix removed the TaskSpec import as unused within the module,
but it is part of the public API — tests import it from scripts.task_scheduler
rather than reaching into circuitforge_core directly.
Add # noqa: F401 to protect intentional re-exports from future auto-fix.

scripts/task_scheduler.py

@@ -21,6 +21,7 @@ from typing import Callable, Optional
 
 from circuitforge_core.tasks.scheduler import (
     LocalScheduler as _CoreTaskScheduler,
+    TaskSpec,  # noqa: F401 — re-exported as part of public API; tests import from here
 )
 
 logger = logging.getLogger(__name__)