feat(#949): install/surface consume derived profiles/clusters (ADR-857 phase 4c) (#954)

Make install + surface read the registry's derived profileMembership/
capabilityClusters so a capability's tier drives what installs + surfaces.
resolveProfile (when given the registry) unions capability skills for the
profiles its tier implies before the requires: closure; resolveSurface merges
capabilityClusters into the cluster map. bin/install.js, /gsd:surface, and the
capability-state resolver all thread the registry.

Shipped as a proven no-op: the UI capability is reconciled to tier:full (its
skills were full-only in the hand-authored profiles), so it contributes only to
the full profile (already the '*' sentinel) and core/standard are unchanged.
Equivalence tests prove resolveProfile/resolveSurface/listSurface/staging/
capability-state are identical with vs without the registry; the core-alias
staging path is verified equivalent (empty manifest → raw PROFILES.core).

Closes #949

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

capabilities/ui/capability.json

@@ -1,7 +1,7 @@
 {
   "id": "ui", "role": "feature", "title": "UI design contracts",
   "description": "UI-SPEC design contract + retrospective UI audit for frontend phases.",
-  "tier": "standard", "requires": [],
+  "tier": "full", "requires": [],
   "skills": ["ui-phase", "ui-review"],
   "agents": ["gsd-ui-checker", "gsd-ui-auditor"],
   "hooks": [],