Duplicates: Yams' duplicate-key error is disarmed by placeholder-
renaming first occurrences and re-composing (line count preserved, so
span layout stays exact); reads take the last occurrence, set()
rewrites the winner and clears earlier twins, remove() clears all.
Top-level only — nested duplicates stay YAML errors (doc updated).
Re-splice: an inline comment on a rewritten scalar line survives, with
quote-aware detection so a # inside quotes is never a comment. +31
tests (118 total).
Claude-Session: https://claude.ai/code/session_018BjQRYBR6jQja3jCRi5S3A
rzen
4085dd7a46