Read, clean, and concatenate every artifact declared by the run's manifest
(with discovery fallback when manifest.files is missing), returning a
single aggregated Markdown document.
The function is deterministic: given the same inputs it produces the
same output byte-for-byte.
Read, clean, and concatenate every artifact declared by the run's manifest (with discovery fallback when manifest.files is missing), returning a single aggregated Markdown document.
The function is deterministic: given the same inputs it produces the same output byte-for-byte.