Read Pipeline Node from a Past Build Run
Reads and returns the contents of a pipeline node from a historical
build log, identified by which_log. Unlike
read_node, this works without the pipeline being in scope —
the node name is captured via NSE from the p.node_name
syntax.
node (ComputedNode): The node to
read, written as p.node_name (NSE-captured).
which_log (String): A regex pattern
matching a specific build log filename.
The deserialized artifact value, wrapped with diagnostics.