feat(advisor): v3 Clarity Gate — Case model + clarify/answer contract, [n] citations

Builds the FE against the SDK<->FE Clarity-Gate contract (board 2026-07-01 /
advisor-clarity-gate-contract). The advisor is now a CASE, not a chat:
- Request {question, context?}; response {mode: clarify|answer, clarity, general_answer,
  answer, evidence, citations, visual_evidence, footnotes}.
- clarify mode: short L1 general answer (marked "allgemeine Definition, ohne Rechtsquelle")
  + domain context chips; picking a chip re-runs the case scoped (-> answer).
- answer mode: markdown answer with clickable [n] citation markers coupled to evidence
  cards (highlight + scroll), evidence grouped by document family, visual_evidence
  (visual_type), footnotes, honest summary counts (no trust score).
- FE never parses the answer for structure — only the deliberate [n] markers, mapped via
  citations[]. New: contract.ts, useAdvisorCase, useCitationHighlight, ClarifyView,
  EvidenceUnitCard, VisualEvidencePane, CaseView. Removed the v2 stream/chat components.

NOT deployed: FE shape-switch (JSON modes) must deploy TOGETHER with the SDK endpoint
delivering the contract (board deploy-coupling). Proxy/route.ts unchanged (SDK-owned).
tsc clean, 16 vitest (incl. clarify+answer fixtures), check-loc 0.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

admin-compliance/components/sdk/advisor/useCitationHighlight.ts

@@ -0,0 +1,34 @@
+'use client'
+
+import { useState } from 'react'
+import type { Citation } from '@/lib/sdk/advisor/contract'
+import type { CiteHandler } from './Markdown'
+
+/**
+ * Couples answer [n] markers to evidence cards: clicking [n] highlights + scrolls to the referenced
+ * evidence unit. Works across layout columns via the card's DOM id (ev-<evidence_id>).
+ */
+export function useCitationHighlight(citations: Citation[]): {
+  highlightedId?: string
+  cite?: CiteHandler
+} {
+  const [highlightedId, setHighlightedId] = useState<string | undefined>()
+  if (citations.length === 0) return { highlightedId }
+  return {
+    highlightedId,
+    cite: {
+      count: citations.length,
+      onSelect: (n: number) => {
+        const c = citations[n - 1]
+        if (!c) return
+        setHighlightedId(c.evidence_id)
+        if (typeof document !== 'undefined') {
+          document.getElementById(`ev-${c.evidence_id}`)?.scrollIntoView({
+            behavior: 'smooth',
+            block: 'center',
+          })
+        }
+      },
+    },
+  }
+}