Added to the fast subset (7 matches, 62 of 151 scenarios). No existing scenario moved (17 matches and every other family byte-identical).
Test: test/golden-diy.test.js.
Conflicts: tools/golden.mjs / test/golden/README.md take both new families (standins from W5G, diy from W5H); DATA.md / SIM.md keep both texts. data/ equals an offline build of the merged tools/build-data.mjs. Golden regenerated on the merged code: against feedback5 nothing moved, diy.json is new; against fb5-diy the W5G / W5J / W5L scenarios moved, and diy-004 / diy-006 (the prototype battles with Touch, changed by W5L) — diy-001/002/003/005 identical.
A new family (test/golden/diy.json): no existing scenario moved (roster 49, bonds 46, fields 22, matches 16 identical); determinism checked with --twice.