The 1123-line collection tier is the largest source file. Cut it at two existing
section banners into 20-coll (predicates, printing, hierarchies, pure-over-core
leaves), 21-coll (rand/sort seams, the test runner, fn combinators), and 22-coll
(canonical Clojure ports, transduce/into, JVM-shape stubs). No macros in this tier,
so order is the only constraint; the emit-image manifest lists the three in
sequence. Re-minted seed is identical apart from gensym label renumbering.