overlays/vr1-dc0-vips.yaml is now fully GUA -- 39/39 v6 VIP legs, zero fd50:. The
renderer reproduces it byte-for-byte and provider-bundle-check PASSES with 13
dual-family VIPs.

Both apex readers had to learn family first. Step 1 creates GUA alongside ULA and step
6 retires ULA, so mid-transition every v6-only plane has two /64s under one (role,kind)
key and both readers could only REFUSE -- measured live: derive --dual-family rc 2, and
the gate "cannot evaluate barbican's dual-family vip". render-dc-overlays gains
--v6-family (refuse on ambiguity kept); provider-bundle-check resolves per application
AND per leg, needing no flag at any call site.

A lossy path was found and NOT taken: a full derive drops the 13 per-app comment fields
(4368 -> 3593 bytes). The values file was edited surgically instead: 26 changed overlay
lines, every comment intact. derive being lossy against its own values file is logged.

PROPERTY TRADED, recorded as a loss not a win: the gate no longer catches a wrong-FAMILY
leg -- a ULA leg in the GUA dc0 overlay now PASSES, graded against the ULA band that
exists until step 6. Necessary (dc1 is legitimately ULA) but it leaves D-139 family
conformance checked by nothing. A ruled-table conformance gate is OWED.

Two bugs I introduced were caught by the harness, not review: family inferred once from
the provider leg (GUA in both worlds -- 7 dc1 cases red), then bands resolved once per
bundle instead of per application.

tests/render-dc-overlays 18 -> 23/23 (3 mutations, restore sha256-identical);
tests/provider-bundle-check 55/55; gauntlet ALL GREEN (96); repo-lint 0 fail / 1 warn.
vr1-dc1 untouched.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HvCyrwvYTTcDYnRErfMsNf