pipeio_nb_exec — execute notebook via papermill with param injection

Goal

(promoted from note)

Context

(see source note)

Prompt

Implement pipeio_nb_exec(pipe, flow, name, params=None, timeout=600) — sync notebook, execute via papermill with optional RunCard parameter overrides, return structured result (status, errors, output path, elapsed time).

Reference capture: 20260325-211509-70e473.

Acceptance Criteria

• [ ]

Result

(pending)