Locks Antigravity as the Declarative-CLI reference host through the public
Host-Integration Interface (#1682 AC): profileOf(antigravity axes) ===
'declarative-cli'; createDeclarativeAdapter({runtime:'antigravity'}) classifies
as kind:'declarative'; a real install emits a gsd command/skill surface (nested
gsd-ns-* router layout). Byte-identity vs today's install stays gated by
golden-install-parity (all 16 runtimes) + adapter-declarative-equivalence.
