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/EvidenceUnitCard.tsx

@@ -0,0 +1,80 @@
+'use client'
+
+import { useState } from 'react'
+import { ChevronDown, ChevronRight, ExternalLink } from 'lucide-react'
+import type { EvidenceUnit } from '@/lib/sdk/advisor/contract'
+import { resolveRegulation } from '@/lib/sdk/advisor/regulation-display'
+
+/** One evidence unit (contract shape). Compact inside a document group: chapter/section only. */
+export function EvidenceUnitCard({
+  unit,
+  compact,
+  highlighted,
+}: {
+  unit: EvidenceUnit
+  compact?: boolean
+  highlighted?: boolean
+}) {
+  const [open, setOpen] = useState(false)
+  const d = resolveRegulation({ code: unit.document, short: unit.document })
+  const crumbs = [unit.section, unit.paragraph].filter((x): x is string => Boolean(x))
+  const canOpen = !!unit.url && /^https?:\/\//i.test(unit.url)
+
+  const header = compact ? (d.chapter ? `Kapitel ${d.chapter}` : crumbs[0] || d.familyLabel) : d.familyLabel
+  const sub = compact && !d.chapter && crumbs.length ? crumbs.slice(1) : crumbs
+
+  return (
+    <div
+      id={`ev-${unit.evidence_id}`}
+      className={`${
+        compact
+          ? 'rounded-md border border-gray-100 bg-gray-50 p-2'
+          : 'rounded-lg border border-gray-200 bg-white p-2.5'
+      } ${highlighted ? 'ring-2 ring-indigo-400' : ''}`}
+    >
+      <div className="flex items-start justify-between gap-2">
+        <div className="min-w-0">
+          <div className="truncate text-xs font-semibold text-gray-900">{header}</div>
+          {sub.length > 0 && (
+            <div className="mt-0.5 flex flex-wrap items-center gap-x-1 text-[11px] text-gray-500">
+              {sub.map((c, i) => (
+                <span key={i} className="flex items-center gap-1">
+                  {i > 0 && <span className="text-gray-300">›</span>}
+                  {c}
+                </span>
+              ))}
+            </div>
+          )}
+        </div>
+        {canOpen && (
+          <a
+            href={unit.url}
+            target="_blank"
+            rel="noopener noreferrer"
+            className="flex flex-shrink-0 items-center gap-0.5 rounded px-1.5 py-0.5 text-[11px] font-medium text-indigo-600 hover:bg-indigo-50"
+          >
+            <ExternalLink className="h-3 w-3" />
+            öffnen
+          </a>
+        )}
+      </div>
+      {unit.snippet && (
+        <div className="mt-1.5">
+          <button
+            type="button"
+            onClick={() => setOpen((v) => !v)}
+            className="flex items-center gap-0.5 text-[11px] text-gray-400 hover:text-gray-600"
+          >
+            {open ? <ChevronDown className="h-3 w-3" /> : <ChevronRight className="h-3 w-3" />}
+            Textauszug
+          </button>
+          {open && (
+            <p className="mt-1 border-l-2 border-gray-200 pl-2 text-[11px] italic text-gray-500">
+              {unit.snippet}
+            </p>
+          )}
+        </div>
+      )}
+    </div>
+  )
+}