leoflow_runtime
Leoflow task runtime: the helper that runs inside every task container.
It runs the user's Python callable, captures its return value as an XCom, and
exposes upstream XCom inputs. The leoflow-agent invokes python -m
leoflow_runtime <module:callable> and ships the captured return value back to
the control plane.
Import and call module:callable, writing a non-None return as JSON.
The agent reads the file and pushes it as the task's return_value XCom.
A None return writes nothing, so downstream tasks see no XCom.
Emits three lifecycle lines so the UI's log panel is informative even when
the user function is silent: loading <entrypoint>, resolved kwargs:
{...} (when any), and returned <repr> (success) or no extra line on
raise (the agent wraps the traceback). All three use [leoflow] prefix
via _lifecycle() so they are distinguishable from user print().
Return the upstream XCom mapped to name, or default if absent.
The agent injects each declared input as LEOFLOW_XCOM_<NAME>=<json>;
the name is matched case-insensitively.