feat(onboarding): surface curated expert text + human capability labels (advisor was showing snake_case)

The advisor was structurally correct but unusable: every question showed a snake_case capability id plus a
single generic fallback reason ("Keine Anhaltspunkte im Unternehmensprofil — klären"). The expert text
already EXISTED in the transition patterns (why_asked / reviewable_claim) — the pipeline just dropped it.

  - transition_reasoning: TargetRequirement gains `rationale`; assess_transition uses it as the request
    reason when present, else the generic fallback (additive, backward-compatible for all consumers).
  - onboarding_service._target carries the pattern's why_asked (delta) and reviewable_claim (likely_covered)
    into the requirement rationale -> the question's `why`.
  - knowledge/onboarding/capability_labels.yaml: curated DE labels (id -> human), reusable across targets;
    labels_for() + response.capability_labels expose them; the frontend renders label || prettified id.

Now ISO27001->TISAX reads "Auftragsverarbeitung (Art. 28 DSGVO) — If a TISAX data label is in scope, you
must show Art. 28 GDPR processing-on-behalf controls; ISO 27001 does not establish these." instead of
"data_protection_processing_on_behalf — klären". why_asked text is still EN (existing knowledge; translation
is curation). 34 onboarding+transition tests pass, mypy --strict clean (13 modules), check-loc 0.

admin-compliance/app/sdk/onboarding-advisor/page.tsx

@@ -29,7 +29,7 @@ interface AdvisorResponse {
   silent_intake_summary: string; headline: string; auto_detected: string[]; indications: string[]
   inferred_assumptions: Inferred[]; rejected_assumptions: Rejected[]; top_5_questions: Question[]
   capability_delta: string[]; top_measures: Measure[]; evidence_requests: string[]
-  unsupported_domains: string[]; completeness_summary: string
+  unsupported_domains: string[]; completeness_summary: string; capability_labels: Record<string, string>
 }
 
 const PROXY = '/api/sdk/v1/compliance/onboarding'
@@ -74,6 +74,8 @@ export default function OnboardingAdvisorPage() {
   const toggle = (list: string[], set: (v: string[]) => void, v: string) =>
     set(list.includes(v) ? list.filter(x => x !== v) : [...list, v])
 
+  const lbl = (id: string) => result?.capability_labels?.[id] || id.replace(/_/g, ' ')
+
   const run = async () => {
     setLoading(true); setError(''); setResult(null)
     try {
@@ -153,15 +155,15 @@ export default function OnboardingAdvisorPage() {
               <div className="text-blue-100 text-sm mt-1">{result.silent_intake_summary}</div>
             </div>
             <div className="grid md:grid-cols-2 gap-4">
-              <Section title="Automatisch erkannt" hint="konkrete Artefakte – nicht mehr gefragt"><Chips items={result.auto_detected} tone="bg-emerald-100 text-emerald-800" /></Section>
-              <Section title="Indikationen" hint="erhöht Annahmestärke – trotzdem gefragt"><Chips items={result.indications} tone="bg-amber-100 text-amber-800" /></Section>
+              <Section title="Automatisch erkannt" hint="konkrete Artefakte – nicht mehr gefragt"><Chips items={result.auto_detected.map(lbl)} tone="bg-emerald-100 text-emerald-800" /></Section>
+              <Section title="Indikationen" hint="erhöht Annahmestärke – trotzdem gefragt"><Chips items={result.indications.map(lbl)} tone="bg-amber-100 text-amber-800" /></Section>
             </div>
             <Section title="Nächste beste Fragen" hint="max 5, jede erklärt sich selbst">
               {result.top_5_questions.length ? (
                 <ol className="space-y-3">
                   {result.top_5_questions.map((q, i) => (
                     <li key={q.capability_id} className="border-l-2 border-blue-300 pl-3">
-                      <div className="font-medium text-gray-900">{i + 1}. {q.capability_id} <span className="text-xs text-gray-500">({q.question_intent})</span></div>
+                      <div className="font-medium text-gray-900">{i + 1}. {lbl(q.capability_id)}</div>
                       <div className="text-sm text-gray-600">{q.why}</div>
                     </li>
                   ))}
@@ -171,7 +173,7 @@ export default function OnboardingAdvisorPage() {
             <div className="grid md:grid-cols-2 gap-4">
               <Section title="Wahrscheinlich abgedeckt (Welt-1)" hint="Zertifikat legt nahe – Verifikation erforderlich">
                 {result.inferred_assumptions.length ? result.inferred_assumptions.map(a => (
-                  <div key={a.certification} className="mb-2"><span className="font-medium">{a.certification}</span>: {a.capabilities.join(', ')}</div>
+                  <div key={a.certification} className="mb-2"><span className="font-medium">{a.certification}</span>: {a.capabilities.map(lbl).join(', ')}</div>
                 )) : <span className="text-gray-400 text-sm">—</span>}
               </Section>
               <Section title="Nicht relevant" hint="relevance(evidence, target) = 0">
@@ -181,7 +183,7 @@ export default function OnboardingAdvisorPage() {
               </Section>
             </div>
             <div className="grid md:grid-cols-2 gap-4">
-              <Section title="Offene Lücken (Delta)"><Chips items={result.capability_delta} tone="bg-gray-100 text-gray-700" /></Section>
+              <Section title="Offene Lücken (Delta)"><Chips items={result.capability_delta.map(lbl)} tone="bg-gray-100 text-gray-700" /></Section>
               <Section title="Geforderte Nachweise"><Chips items={result.evidence_requests} tone="bg-gray-100 text-gray-700" /></Section>
             </div>
             <Section title="Vollständigkeit" hint={result.unsupported_domains.length ? `nicht abgedeckt: ${result.unsupported_domains.join(', ')}` : undefined}>