crates/idml/src/lib.rs: crate doc keeps the branch's feather list and adds liquid guides.
crates/idml/src/tests.rs: keep all test modules from both sides.
docs/file-format-parity.md: keep both change-log rows; status line names both changes.
ROADMAP.md: drop the blank line the union merge left inside the progress log, and a stray one further down.