SourceSpan missing absolute input index

SourceSpan missing absolute input index: a task in LegoFlow-SWE (Harbor dataset). Currently, SourceSpan records line index, column index, and length of a parsed range, but it does not expose the absolute character index within the original input string. This makes it difficult for callers to map…

The task

Currently, `SourceSpan` records line index, column index, and length of a parsed range, but it does not expose the absolute character index within the original input string. This makes it difficult for callers to map parsed nodes back to the original source using operations like substring without first splitting the…

Part of Lego-X/LegoFlow-SWE.