be2c2beb96
The batch tool_status values ('completed'/'error'/'pending') and the inbound
status alias sets were inline magic strings, duplicated across two checks in
_tool_result_status. Hoist them to module-level constants
(_TOOL_STATUS_* + _TOOL_STATUS_{ERROR,COMPLETED}_ALIASES) so the canonical
wire values and the alias->canonical mapping live in one place. Emitted
values are unchanged.